Touch panel

ABSTRACT

A touch panel with higher sensing accuracy or higher detection sensitivity is provided. The touch panel includes a first conductive layer, a second conductive layer, a plurality of display elements, and a scan line. In a plan view, the first conductive layer has an outline including a first portion that is linear and parallel to a first direction. In the plan view, the second conductive layer has an outline including a second portion that is linear and parallel to the first direction. The first portion and the second portion face each other. The display element is in a position not overlapping with the first conductive layer nor the second conductive layer. The scan line has a portion extending in a second direction. An angle between the first direction and the second direction is greater than or equal to 30° and less than or equal to 60°.

BACKGROUND OF THE INVENTION

1. Field of the Invention

One embodiment of the present invention relates to an input device. Oneembodiment of the present invention relates to a display device.Further, one embodiment of the present invention relates to aninput/output device. In particular, one embodiment of the presentinvention relates to a touch panel.

Note that one embodiment of the present invention is not limited to theabove technical field. Examples of the technical field of one embodimentof the present invention include a semiconductor device, a displaydevice, a light-emitting device, a power storage device, a storagedevice, an electronic device, a lighting device, an input device, aninput/output device, a driving method thereof, and a manufacturingmethod thereof.

In this specification and the like, a semiconductor device generallymeans a device that can function by utilizing semiconductorcharacteristics. A semiconductor element such as a transistor, asemiconductor circuit, an arithmetic device, and a memory device areeach an embodiment of a semiconductor device. An imaging device, adisplay device, a liquid crystal display device, a light-emittingdevice, an input device, an input/output device, an electro-opticaldevice, a power generation device (including a thin film solar cell, anorganic thin film solar cell, and the like), and an electronic devicemay each include a semiconductor device.

2. Description of the Related Art

In recent years, a display device provided with a touch sensor as aposition-input device has been in practical use. A display deviceprovided with a touch sensor is called a touch panel, a touch screen, orthe like (hereinafter also referred to simply as a touch panel). Forexample, a smartphone and a tablet terminal are examples of a portableinformation terminal provided with a touch panel.

Examples of the display device include, typically, a liquid crystaldisplay device, a light-emitting device including a light-emittingelement such as an organic electroluminescent (EL) element or alight-emitting diode (LED), and electronic paper performing display byan electrophoretic method or the like.

For example, in a basic structure of an organic EL element, a layercontaining a light-emitting organic compound is provided between a pairof electrodes. By voltage application to this element, thelight-emitting organic compound can emit light. A display deviceincluding such an organic EL element needs no backlight which isnecessary for liquid crystal display devices and the like; therefore,thin, lightweight, high contrast, and low power consumption displaydevices can be obtained. Patent Document 1, for example, discloses anexample of a display device using organic EL elements.

In a touch panel, a pressure-sensitive sensor array or a capacitivesensor array is provided so as to overlap with a display panel, forexample; by touching a substrate of the sensor array with a finger or aninput pen (also referred to as a stylus), the touched position issensed.

Patent Document 2 discloses a structure of a touch panel in which atouch sensor is provided on a display screen of an electroluminescencedisplay device.

REFERENCE Patent Document

[Patent Document 1] Japanese Published Patent Application No.2002-324673

[Patent Document 2] Japanese Published Patent Application No.2000-172444

SUMMARY OF THE INVENTION

In order to obtain positional information of an object touching a touchsensor or a touch panel more precisely, a touch sensor with highersensitivity is required.

An object of one embodiment of the present invention is to provide aninput device or an input/output device with higher sensing accuracy.Another object is to provide an input device or an input/output devicewith higher detection sensitivity. Another object is to provide a novelinput device or a novel input/output device.

Note that the descriptions of these objects do not disturb the existenceof other objects. In one embodiment of the present invention, there isno need to achieve all the objects. Other objects can be derived fromthe description of the specification, the drawings, the claims, and thelike.

One embodiment of the present invention is a touch panel including afirst conductive layer, a second conductive layer, a plurality ofdisplay elements, and a scan line. In a plan view, the first conductivelayer has an outline including a first portion that is linear andparallel to a first direction. In the plan view, the second conductivelayer has an outline including a second portion that is linear andparallel to the first direction. The first portion and the secondportion face each other. The display element is in a position notoverlapping with the first conductive layer nor the second conductivelayer. The scan line has a portion extending in a second direction. Anangle between the first direction and the second direction is greaterthan or equal to 30° and less than or equal to 60°.

In the above touch panel, the first conductive layer and the secondconductive layer each have a lattice shape where strips parallel to thefirst direction and strips parallel to a direction perpendicular to thefirst direction intersect with each other with openings between them.The opening and the display element preferably overlap with each other.

In the above touch panel, the display element preferably has a polygonalshape whose two sides are parallel to the first direction in the planview.

The above touch panel preferably includes a first substrate and a secondsubstrate that sandwich the first conductive layer, the secondconductive layer, the display element, and the scan line. It ispreferable that a light-blocking layer capable of blocking visible lightbe further included. In addition, it is preferable that the firstsubstrate be provided with the display element and the scan line, andthe second substrate be provided with the first conductive layer, thesecond conductive layer, and the light-blocking layer. Here, thelight-blocking layer is preferably between the first conductive layerand the second substrate, and between the second conductive layer andthe second substrate.

In the above touch panel, the first conductive layer and the secondconductive layer are preferably in the same plane.

In the above touch panel, a distance between the first portion and thesecond portion is preferably greater than or equal to 1 μm and less thanor equal to 10 mm.

Another embodiment of the present invention is a touch panel moduleincluding the above touch panel and an FPC.

Another embodiment of the present invention is an electronic deviceincluding the above touch panel or the above touch panel module, and atleast one of an antenna, a button, a battery, a speaker, a microphone,and a lens.

According to one embodiment of the present invention, an input device oran input/output device with higher sensing accuracy can be provided.Alternatively, an input device or an input/output device with higherdetection sensitivity can be provided. Alternatively, a novel inputdevice or a novel input/output device can be provided.

Note that the descriptions of these effects do not disturb the existenceof other effects. One embodiment of the present invention does notnecessarily achieve all the effects listed above. Other effects can bederived from the description of the specification, the drawings, theclaims, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B illustrate a structure example of a touch panel of oneembodiment.

FIGS. 2A and 2B illustrate a structure example of an input device of oneembodiment.

FIG. 3 illustrates a structure example of an input device of oneembodiment.

FIGS. 4A to 4C illustrate a structure example of an input device of oneembodiment.

FIGS. 5A and 5B each illustrate a structure example of an input deviceof one embodiment.

FIGS. 6A and 6B each illustrate a structure example of an input deviceof one embodiment.

FIGS. 7A to 7C each illustrate a structure example of an input device ofone embodiment.

FIGS. 8A and 8B each illustrate a structure example of an input deviceof one embodiment.

FIGS. 9A to 9F each illustrate a structure example of an input device ofone embodiment.

FIG. 10 illustrates a structure example of a touch panel of oneembodiment.

FIGS. 11A to 11F each illustrate a structure example of a touch panel ofone embodiment.

FIG. 12 illustrates a structure example of a touch panel of oneembodiment.

FIGS. 13A to 13D each illustrate a structure example of a touch panel ofone embodiment.

FIG. 14 illustrates a structure example of a touch panel of oneembodiment.

FIG. 15 illustrates a structure example of a touch panel of oneembodiment.

FIG. 16 illustrates a structure example of a touch panel of oneembodiment.

FIG. 17 illustrates a structure example of a touch panel of oneembodiment.

FIG. 18 illustrates a structure example of a touch panel of oneembodiment.

FIG. 19 illustrates a structure example of a touch panel of oneembodiment.

FIG. 20 illustrates a structure example of a touch panel of oneembodiment.

FIG. 21 illustrates a structure example of a touch panel of oneembodiment.

FIG. 22 illustrates a structure example of a touch panel of oneembodiment.

FIG. 23 illustrates a structure example of a touch panel of oneembodiment.

FIG. 24 illustrates a structure example of a touch panel of oneembodiment.

FIG. 25 illustrates a structure example of a touch panel of oneembodiment.

FIG. 26 illustrates a structure example of a touch panel of oneembodiment.

FIG. 27 illustrates a structure example of a touch panel of oneembodiment.

FIGS. 28A and 28B are a block diagram and a timing chart of a touchsensor of one embodiment.

FIG. 29 is a circuit diagram of a touch sensor of one embodiment.

FIGS. 30A and 30B illustrate a pixel provided with a touch sensor of oneembodiment.

FIGS. 31A and 31B illustrate operation of a touch sensor and a pixel ofone embodiment.

FIGS. 32A to 32H illustrate examples of electronic devices and lightingdevices of one embodiment.

FIGS. 33A to 331 illustrate examples of electronic devices of oneembodiment.

FIGS. 34A to 34E illustrate examples of electronic devices of oneembodiment.

FIGS. 35A to 35C illustrate examples of electronic devices of oneembodiment.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments will be described in detail with reference to drawings. Notethat the present invention is not limited to the description below, andit is easily understood by those skilled in the art that various changesand modifications can be made without departing from the spirit andscope of the present invention. Accordingly, the present inventionshould not be interpreted as being limited to the content of theembodiments below.

Note that in the structures of the invention described below, the sameportions or portions having similar functions are denoted by the samereference numerals in different drawings, and description of suchportions is not repeated. Further, the same hatching pattern is appliedto portions having similar functions, and the portions are notespecially denoted by reference numerals in some cases.

Note that in each drawing described in this specification, the size, thelayer thickness, or the region of each component is exaggerated forclarity in some cases. Therefore, embodiments of the present inventionare not limited to such a scale.

Note that in this specification and the like, ordinal numbers such as“first”, “second”, and the like are used in order to avoid confusionamong components and do not limit the number.

A transistor is a kind of semiconductor elements and can achieveamplification of current or voltage, switching operation for controllingconduction or non-conduction, or the like. A transistor in thisspecification is an insulated-gate field effect transistor (IGFET) or athin film transistor (TFT), for example.

Embodiment 1

In this embodiment, a structure example of an input device (a touchsensor) of one embodiment of the present invention, and a structureexample of an input/output device (a touch panel) including the inputdevice of one embodiment of the present invention and a display device(a display panel) are described with reference to drawings.

In the description below, a capacitive touch sensor is used as the touchsensor of one embodiment of the present invention.

Note that in this specification and the like, a touch panel has afunction of displaying or outputting an image or the like on or to adisplay surface and a function as a touch sensor capable of detectingcontact or proximity of an object such as a finger or a stylus on or tothe display surface. Therefore, the touch panel is an embodiment of aninput/output device.

In this specification and the like, a structure in which a connectorsuch as a flexible printed circuit (FPC) or a tape carrier package (TCP)is attached to a substrate of a touch panel, or a structure in which anintegrated circuit (IC) is directly mounted on a substrate by a chip onglass (COG) method is referred to as a touch panel module or simplyreferred to as a touch panel in some cases.

A capacitive touch sensor that can be used for one embodiment of thepresent invention includes a pair of conductive layers. A capacitor isformed in the pair of conductive layers. The capacitance of the pair ofconductive layers changes when an object touches or gets close to thepair of conductive layers. Utilizing this effect, detection can beconducted.

Examples of the capacitive touch sensor are a surface capacitive touchsensor and a projected capacitive touch sensor. Examples of a projectedcapacitive touch sensor are a self-capacitive touch sensor and a mutualcapacitive touch sensor. The use of a mutual capacitive touch sensor ispreferable because multiple points can be detected simultaneously.

The two conductive layers each have an outline including linear portionswhen viewed in a plan view. The linear portions of the two conductivelayers face and are parallel to each other. With such a structure, thecapacitance between the two conductive layers can be increased. In aportion where the two conductive layers face and are parallel to eachother, electrical lines of force generated when a potential differenceis applied between the two conductive layers are distributed at auniform density. Therefore, the difference of detection sensitivitydepending on positions can be reduced. Thus, a touch sensor with highersensing accuracy can be obtained.

The touch panel of one embodiment of the present invention includes thetouch sensor and a display panel (a display device) that displays animage. The touch sensor is provided to overlap with a display surface ofthe display panel.

In addition, it is preferable that a display element of the displaypanel and the pair of conductive layers of a touch sensor be providedwithout overlapping with each other. With such a structure, a decreaseof luminance of an image displayed on the touch panel can be prevented,and the touch panel can have higher visibility. Furthermore, powerconsumption can be reduced.

The direction of the linear portions of the pair of conductive layers ispreferably inclined at approximately 45° to a horizontal direction or aperpendicular direction of a display image displayed on the displaypanel. For example, an angle between an extending direction of a scanline (also referred to as a gate line) in the display panel and adirection of the linear portion of the conductive layer is preferablygreater than or equal to 40° and less than or equal to 50°.

The pair of conductive layers preferably has a lattice (mesh) shape;such a structure can increase the conductivity of the conductive layers.When the pair of conductive layers has a lattice shape, it is preferablethat there be portions extending in a direction parallel to the linearportion and portions extending in a direction perpendicular to thelinear portion in the lattice shape.

When the pair of conductive layers has a lattice shape, an opening ofthe lattice and the display element preferably overlap with each otherin a plan view. Here, the display element preferably has a polygonaloutline including a side parallel to the extending direction of theportion of the lattice in a plan view. Such a structure will increase anaperture ratio. Alternatively, the display element preferably has apolygonal outline including two sides parallel to the extendingdirection of the linear portion of the conductive layer or has anoutline of closed line including a linear portion in a plan view.

Specifically, the following structure can be employed, for example.

[Structure Example]

As an example of an input/output device of one embodiment of the presentinvention, structure examples of a touch panel are described below withreference to drawings.

[Structure Example of Touch Panel]

FIG. 1A is a schematic perspective view of a touch panel 100 of oneembodiment of the present invention. FIG. 1B is a schematic perspectivedeveloped view of FIG. 1A. Note that only main components areillustrated for simplicity. In FIG. 1B, as to some components (asubstrate 30, a substrate 72, and the like), only their outlines areshown by broken lines.

The touch panel 100 includes an input device 10 and a display panel 70that overlap with each other.

In this example, the input device 10 includes the substrate 30. Thesubstrate 30 includes an electrode 31, an electrode 32, a plurality ofwirings 41, and a plurality of wirings 42. In addition, an FPC 50 towhich the plurality of wirings 41 and the plurality of wirings 42 areelectrically connected is attached to the substrate 30. An IC 51 isprovided over the FPC 50.

As the input device 10, a capacitive touch sensor can be used, forexample. An example of using a projected capacitive touch sensor will bedescribed below.

As the input device 10, any of various sensors that can sense theproximity or contact of an object such as a finger or a stylus can beused.

Note that a specific structure of the input device 10 will be describedlater.

In this example, the display panel 70 includes a substrate 71 and asubstrate 72 that face each other. A display portion 81, a drivercircuit 82, a wiring 83 and the like are provided over the substrate 71.An FPC 73 electrically connected to the wiring 83 is provided to thesubstrate 71. An IC 74 is provided over the FPC 73.

The display portion 81 is a region where an image is displayed, andincludes a plurality of pixels. FIG. 1B is a schematic view illustratingenlarged part of the display portion 81. The pixel includes at least onedisplay element 60. The pixel preferably includes a transistor and thedisplay element 60. As the display element 60, typically, alight-emitting element such as an organic EL element, a liquid crystalelement, or the like can be used.

For the driver circuit 82, a circuit that can drive the pixels in thedisplay portion 81, such as a scan line driver circuit or a signal linedriver circuit, can be used. Here, an example where a scan line drivercircuit is used as the driver circuit 82 is described.

The wiring 83 is capable of transferring a signal or an electric powerto the display portion 81 or the driver circuit 82. The signal or theelectric power is input from the outside or the IC 74 to the wiring 83through the FPC 73.

The display portion 81 includes a plurality of scan lines (also referredto as gate lines) 87 that are electrically connected to the drivercircuit 82. The scan line 87 is a wiring that is electrically connectedto a gate of a transistor in the pixel. The driver circuit 82 cansequentially supply the scan lines 87 with signals each of which selectsa plurality of pixels electrically connected to the scan line 87.

Here, an extending direction of the scan line 87 is shown as a direction80 with an arrow in FIG. 1B. In the structure shown in FIG. 1B, thedirection 80 is parallel to a direction perpendicular to a side(outline) where the driver circuit 82 of the display portion 81 isprovided. When the outline of the display portion 81 is not a rectangleor a square, the direction 80 is not perpendicular to the outline of thedisplay portion 81 in some cases. The scan line 87 is not necessarilylinear, and may have a shape partly curving or twisting depending on thestructure of the pixels. At this time, the direction 80 corresponds to adirection of a line connecting two end points of the scan line 87.Alternatively, the direction 80 corresponds to a direction of a lineconnecting two end portions of part of the scan line 87 that overlapswith the display portion 81. Alternatively, the direction 80 can beregarded as a direction parallel to an arrangement direction of thepixels (or subpixels) electrically connected to one scan line 87.

FIGS. 1A and 1B show an example where the IC 74 is mounted on the FPC 73by a chip on film (COF) method. An IC serving as a scan line drivercircuit, a signal line driver circuit, or the like can be used for theIC 74. Note that it is possible that the IC 74 is not provided when, forexample, the display panel 70 includes circuits serving as a scan linedriver circuit and a signal line driver circuit and when the circuitsserving as a scan line driver circuit and a signal line driver circuitare provided outside and a signal for driving the display panel 70 isinput through the FPC 73. Alternatively, the IC 74 may be directlymounted on the substrate 71 by a COG method or the like.

[Structure Example of Input Device]

FIG. 2A is a schematic top plan view of the input device 10. The inputdevice 10 includes the plurality of electrodes 31, the plurality ofelectrodes 32, the plurality of wirings 41, and the plurality of wirings42 over the substrate 30. In addition, the substrate 30 is provided withthe FPC 50 that is electrically connected to the plurality of wirings 41and the plurality of wirings 42. FIG. 2A shows an example where the IC51 is mounted on the FPC 50. Note that the outline of the electrode 32and that of the electrode 31 are shown by the solid line and the brokenline, respectively, to be distinguished clearly.

In FIG. 2A, the electrode 31 is positioned to extend horizontally. Theelectrode 32 is positioned to extend in a direction intersecting withthe electrode 31. As shown in FIG. 2A, it is preferable that theelectrode 31 and the electrode 32 be perpendicular to each other.

Each of the plurality of wirings 41 is electrically connected to one ofthe electrodes 31. Each of the plurality of wirings 42 is electricallyconnected to one of the electrodes 32.

The IC 51 includes a circuit for driving the input device 10. The IC 51includes, for example, a circuit for achieving a driving method, such asa mutual capacitive method or a self-capacitive method.

FIG. 2B is an enlarged view of a region P of FIG. 2A. The electrode 31and the electrode 32 overlap with and intersect with each other at anintersection portion 90. At the intersection portion 90, an insulator isprovided between the electrodes 31 and 32 in order to prevent theelectrodes 31 and 32 from being short-circuited.

FIG. 2B shows the case where the electrode 32 locally has the same shapeas the 90°-rotated electrode 31.

In a plan view, a plurality of rhombic patterns is connected in line,horizontally or vertically, to make the electrode 31 or the electrode32. At this time, each rhombic pattern is preferably a square as shownin FIG. 2B, whereby a pitch of rhombic patterns of the electrode 31arranged in a horizontal direction and a pitch of rhombic patterns ofthe electrode 32 arranged in a vertical direction in a view can be equalto each other. In this way, detecting points can be arranged at equalintervals in a sensing region of the input device 10, so that sensingaccuracy can be increased.

Part of the outline of the electrode 31 has a linear portion 21. Part ofthe outline of the electrode 32 has a linear portion 22. The electrodes31 and 32 are positioned such that the linear portions 21 and 22 faceand are parallel to each other. With such a structure, a constant gap isobtained between the electrodes 31 and 32, and the length of the facingsides of the two electrodes can be increased. Therefore, the capacitanceformed between the two electrodes can be increased. In a portion wherethe two electrodes face each other, electrical lines of force generatedwhen a potential difference is applied between the two electrodes aredistributed at a uniform density. Therefore, the difference of detectionsensitivity depending on positions can be reduced. Thus, a touch sensorwith higher sensing accuracy can be obtained.

As shown in FIG. 3, either the electrodes 31 or the electrodes 32 may beprovided over the substrate 30. At this time, the other electrode may beprovided on or in the display panel 70. For example, a common electrodeof a liquid crystal element may be utilized as the electrode 31 or theelectrode 32. Though the electrode 31 is provided over the substrate 30in FIG. 3, the electrode 32 may be provided over the substrate 30.

FIG. 2B illustrates the direction 80 shown in FIG. 1B that is theextending direction of the scan line 87. When the linear portions 21 and22 are parallel to each other, an angle between the direction 80 and thelinear portion 21 and an angle between the direction 80 and the linearportion 22 are equal to each other. Here, an angle between the direction80 and the linear portion 21 or 22 is expressed as an angle θ. The angleθ is preferably greater than or equal to 30° and less than or equal to60°, preferably greater than or equal to 40° and less than or equal to50°, more preferably greater than or equal to 42° and less than or equalto 48°, and typically 45°.

A gap between the electrodes 31 and 32 is expressed as a gap D. As thegap D is smaller, the capacitance between the two electrodes can beincreased and thus the detection sensitivity can be increased. The sizeof the gap D is, for example, greater than 0 mm and less than or equalto 10 mm, preferably greater than or equal to 1 μm and less than orequal to 5 mm, more preferably greater than or equal to 3 μm and lessthan or equal to 1 mm, or still more preferably greater than or equal to5 μm and less than or equal to 500 μm. Alternatively, the gap D may bethe integral multiple of a pitch of arranged subpixels or the integralmultiple of a pitch of the arranged display elements 60.

FIG. 2B shows an example where the electrodes 31 and 32 each have alattice shape. The integral multiple of a lattice spacing of theelectrode 31 or 32 is preferably equal to the gap D between theelectrodes 31 and 32. When the electrodes 31 and 32 have orthogonallattice shapes as shown in FIG. 2B, one of two directions of the latticeis preferably parallel to the linear portion 21 or the linear portion22. At this time, openings in the electrodes 31 and 32 are squaresinclined at the angle θ to the direction 80.

Although an opening in the lattice is a square in FIG. 2B, the shape ofthe opening is not limited thereto and can have any of various shapes,such as a circle, an ellipse, and a polygon with rounded corners.

It is preferable that the electrodes 31 and 32 have been processed to benarrow enough not to be viewed from a user. When the electrodes 31 and32 are processed to have a lattice (mesh) shape as shown in FIG. 2B,high conductivity and high visibility of the display device can beobtained. The widths of the narrowest portions of the electrodes 31 and32 are preferably greater than or equal to 30 nm and less than or equalto 100 μm, preferably greater than or equal to 50 nm and less than orequal to 50 μm, or more preferably greater than or equal to 50 nm andless than or equal to 20 μm. In particular, the conductive film with apattern width of 10 μm or less is preferable because the conductive filmwith such a width is rarely recognized by a user.

A conductive nanowire may be used for the electrodes 31 and 32. Whennanowires are dispersed at an appropriate density such that adjacentnanowires are in contact with each other, a two-dimensional network isformed and works as a conductive film with an extremely highlight-transmitting property. For example, a nanowire with an averagediameter of greater than or equal to 1 nm and less than or equal to 100nm, preferably greater than or equal to 5 nm and less than or equal to50 nm, or more preferably greater than or equal to 5 nm and less than orequal to 25 nm can be used. As the nanowire, a carbon nanotube or ametal nanowire such as an Ag nanowire, a Cu nanowire, and an Al nanowirecan be used. For example, in the case of using an Ag nanowire, lighttransmittance of 89% or more and a sheet resistance of 40 ohm/square ormore and 100 ohm/square or less can be achieved.

As shown in FIG. 4A, the electrode 32 may be composed of a plurality ofelectrodes 33 and a bridge electrode 34. For easy understanding of arelative position of the electrode 33 and the bridge electrode 34, onlythe bridge electrode 34 is shown by a broken line in FIG. 4B while onlythe bridge electrode 34 is shown by a solid line in FIG. 4C. There is noparticular limitation on the formation order of the bridge electrode 34and the electrodes 31 and 33, and either the bridge electrode 34 or theelectrodes 31 and 33 may be provided on the substrate 30 side.

The island-shaped electrodes 33 are arranged in a vertical direction,and the two adjacent electrodes 33 are electrically connected to eachother by the bridge electrode 34. With such a structure, the electrodes33 and 31 can be formed at a time by processing the same conductivefilm. Therefore, variations in their film thicknesses or line widths canbe reduced, and variations in the resistance of each electrode dependingon positions can be suppressed. In addition, with such a structure, theelectrodes 33 and 31 can be arranged in the same plane. Thus, theelectrodes 31 and 33 are not misaligned in a height direction, wherebyelectrical lines of force generated therebetween can be uniformlydistributed and the detection sensitivity of the input device 10 can beincreased.

Although the electrode 32 has the bridge electrode 34 here, theelectrode 31 may have such a structure. At that time, when the influenceof the contact resistance become noticeable because of provision of thebridge electrode 34, a structure with the bridge electrodes 34 ispreferably employed for the electrode 31 or 32, whichever is shorter, sothat the number of bridge electrodes 34 in the one electrode can bereduced.

FIG. 5A is an enlarged view of a region Q of FIG. 2A. The region Q is aregion including a corner portion of the sensing region of the inputdevice 10.

As shown in FIG. 5A, the electrodes 31 and 32 preferably have shapes ineach of which an end portion is apparently cut parallel to orperpendicular to the direction 80 at the corner portion of the sensingregion. The outlines of the electrodes 31 and 32 preferably have linearportions parallel to or perpendicular to the direction 80. With such astructure, the bezel of the touch panel 100 where the input device 10and the display panel 70 are combined can be narrowed.

FIG. 5B shows the case where the gap D is wider than that of FIG. 5A.When the gap between the electrodes 31 and 32 is wide like this, theintersection portion 90 preferably has a lattice shape. FIG. 5B showsthat the electrode 32 has the bridge electrode 34 with the latticeshape. When the bridge electrode 34 is not used as shown in FIG. 2B,each of the electrodes 31 and 32 may have a lattice shape at theintersection portion 90.

The case where the electrodes 31 and 32 have the lattice shapes is shownabove, but the shapes of the electrodes 31 and 32 are not limitedthereto and can have any of other various shapes as long as they havefacing linear portions.

In addition, as shown in FIGS. 6A and 6B, a dummy electrode 35 that iselectrically isolated from the electrodes 31 and 32 may be positionedbetween the electrodes 31 and the electrode 32. With such a structure, aregion where neither the electrode 31 nor the electrode 32 exists isless likely to be recognized by a user.

FIG. 7A shows the case where the insides of the rhombic patterns of theelectrodes 31 and 33 of FIG. 4A are hollow and only the outlines thereofare formed. FIG. 7B shows the case where only the linear portions of thelattices in a certain direction remain in the electrodes 31 and 33. FIG.7C shows the case where the electrodes 31 and 33 include zigzagpatterns. In that case, the linear portions of the zigzag patterns arepreferably parallel to the linear portions of the outline of theelectrode 31 or 33. In addition, the zigzag patterns are preferablypositioned to extend in the extending direction of the electrode 31 or32 as shown in FIG. 7C, whereby electric resistance in the direction canbe reduced.

Although the electrode 32 has the bridge electrode 34 in FIGS. 7A to 7C,the bridge electrode 34 is not necessarily provided as shown in FIG. 2B.

Although FIG. 2A and the like show the case where a plurality ofrhombuses are connected in line is shown as a top surface shape of theelectrode 31 or 32, the shapes of the electrodes 31 and 32 are notlimited thereto and can have any of various top surface shapes, such asa stripe (rectangle) shape, a stripe shape with curves, or a zigzagshape. In addition, though the electrodes 31 and 32 are positioned to beperpendicular to each other above, they are not necessarily positionedto be perpendicular to each other and an angle between the twoelectrodes may be less than 90°.

FIG. 8A shows an example where electrodes 36 and 37 with zigzag topsurface shapes are used. For clarification, in FIG. 8A and the like, theelectrode 36 and the electrode 37 are shown by the broken line and thesolid line, respectively. Here, as shown in FIG. 8A, it is preferablethat the electrodes be positioned such that the center portion of alinear portion in the zigzag shape of one electrode not overlap withthat of a linear portion in the zigzag shape of the other electrode, andthe center portions be relatively off from each other. With such apreferable structure, the portions of the electrodes 36 and 37 that faceand are parallel to each other can be close to each other, and thecapacitance formed between the electrodes and the detection sensitivitycan be increased. Alternatively, when part of the linear portions of thezigzag shapes projects in the top surface shapes of the electrodes 36and 37 as shown in FIG. 8B, the capacitance between the electrodes canbe increased because the length of the facing sides can be increasedeven if the center portions of the linear portions overlap with eachother.

FIG. 9A is an enlarged view of a region surrounded by a chain line inFIG. 8A, and FIG. 9D is an enlarged view of a region surrounded by achain line in FIG. 8B. Each drawing shows the electrode 36, theelectrode 37, and an intersection portion 38 where these electrodesintersect with each other. Here, the linear portions of the electrodes36 and 37 of FIGS. 9A and 9D may have meander shapes with angled cornersas shown in FIGS. 9B and 9E. Alternatively, the linear portions of theelectrodes 36 and 37 may have continuously-curved meander shapes asshown in FIGS. 9C and 9F.

That is the description of the structure examples of the input device.

[Structure Example of Pixel]

Structure examples of a pixel in the display panel 70 in the touch panel100 of one embodiment of the present invention are described below.

As described above, there is a plurality of pixels in the displayportion of the display panel 70. A pixel includes one or more displayelements 60. If the display panel 70 displays a full color image, astructure where the display elements 60 for exhibiting three colors ofred (R), green (G), and blue (B) are provided in one pixel ispreferable, for example. A structure where the display elements 60 forexhibiting yellow (Y) and white (W) are provided in addition to thedisplay elements for the above three colors is also preferable becausepower consumption can be reduced. Here, a structure including onedisplay element 60 and a pixel circuit corresponding thereto is referredto as a subpixel in some cases. When a pixel includes the three displayelements 60, the pixel can have a structure with three subpixels.

When the input device 10 overlaps with the display panel 70, it ispreferable that the electrodes 31 and 32 in the input device 10 bepositioned between the display elements 60. Then, the electrodes 31 and32 do not block light from the display elements 60, whereby it ispossible to almost completely avoid, or greatly reduce luminancedecrease in the display panel 70 provided with the input device 10.Therefore, a touch panel with high visibility and low power consumptioncan be achieved. In addition, since the electrodes 31 and 32 do notoverlap with the display element 60, it is not necessary to use alight-transmitting conductive material, which has relatively highresistance, for the electrodes 31 and 32. Therefore, it is possible touse a metal or an alloy material with low resistance for the electrodes31 and 32, and thus it is possible to make the electrodes 31 and 32extremely thin so as not to be recognized by bare eyes. Thus, theelectrodes 31 and 32 are less likely to be recognized by lightreflection or the like, whereby a touch panel with higher visibility canbe obtained.

FIG. 10 is an enlarged view of the display portion 81 and the inputdevice 10 that overlap with each other when viewed from the displaysurface side of the touch panel 100 of FIG. 1A. Here, a pixel 40 in thedisplay panel 70 includes four display elements 60 exhibiting differentcolors (a display element 60R, a display element 60G, a display element60B, and a display element 60Y). Hereinafter, description is made forthe display element 60 when matters common to the four kinds of displayelements are described.

FIG. 10 shows a positional relationship between the electrode 31 and thedisplay elements 60. Note that the electrode 31 is illustrated here, butthe same applies to the electrode 32 (or the electrode 33 and the bridgeelectrode 34). In FIG. 10, for describing a direction of scan lines 87in the display panel 70, three scan lines (a scan line 87 a, a scan line87 b, and a scan line 87 c) are shown by broken lines, and the direction80 that is the extending direction of the scan lines is also shown.

In a structure in FIG. 10, an angle between a linear portion of thelattice of the electrode 31 and the scan line 87 is 45°. The displayelements 60 are arranged along the linear portion of the electrode 31.Here, a plurality of display elements 60 arranged obliquely in FIG. 10are two kinds of display elements 60 exhibiting different two colorsthat are alternately arranged. One pixel 40 includes the four adjacentdisplay elements 60 (display elements 60R, 60G, 60B, and 60Y). Here, thedisplay elements 60R, 60G, 60B, and 60Y are display elements exhibitingred, green, blue, and yellow, respectively.

An outline of one display element 60 preferably has a portion parallelto the linear portion of the lattice of the electrode 31. With such aform, a gap between the two display elements 60 can be reduced when thedisplay elements 60 are arranged, whereby an aperture ratio can beincreased. Although the outline of the display element 60 is aquadrangle with rounded corners, the outline shape is not limitedthereto, and may be a square, a rectangle, a polygon, an ellipse, acircle, a polygon with rounded corners, or the like.

The scan line 87 a in FIG. 10 corresponds to a scan line for driving asubpixel including the display element 60R, for example. The scan line87 b corresponds to a scan line for driving a subpixel including thedisplay element 60G and a subpixel including the display element 60Y Thescan line 87 c corresponds to a scan line for driving a subpixelincluding the display element 60B. Each scan line is electricallyconnected to a gate of a transistor in each subpixel. That is, in thestructure shown in FIG. 10, one pixel can be driven by the three scanlines 87.

In FIG. 10, a structure where one pixel 40 (that is, four displayelements 60) is included in an opening of the electrode 31 is shown;however, the structure of the electrode 31 is not limited thereto, andmay be any of various structures as long as the electrode 31 isconfigured to be positioned between the adjacent display elements 60.

FIG. 11A shows the case where an opening of the lattice of the electrode31 includes one display element 60. FIG. 11B shows the case where theelectrode 31 has a stripe shape. FIG. 11C shows the case where anopening of the lattice of the electrode 31 includes a plurality ofpixels 40. FIG. 11D shows the case where a pitch of the lattice in onedirection is different from a pitch of the lattice in another directionperpendicular to the one direction. FIGS. 11E and 11F show the casewhere the electrode 31 has a zigzag shape like that shown in FIG. 7C.

FIG. 10 and FIGS. 11A to 11F show examples where one pixel 40 includesthe display elements 60 of four colors, but the number of colors ofdisplay elements in a pixel is not limited thereto, and the displayelements of three colors, five colors, or more may be provided.

FIG. 12 shows the case where one pixel 40 includes the display elements60 of three colors. For simplifying the description, a pixel 40 a, apixel 40 b, and a pixel 40 c are shown separately from the others andthree display elements 60 in each of the pixels 40 a, 40 b, and 40 c areshown by the same hatching pattern in FIG. 12.

As to the pixels 40 a and 40 b that are aligned in a vertical direction,arrangement of the three display elements 60 in the pixel 40 a is thesame as that in the pixel 40 b. As to the pixels 40 a and 40 c that arealigned in a horizontal direction, the arrangement of the three displayelements 60 in the pixel 40 a is in a vertically inverse relation tothat in the pixel 40 c.

In FIG. 12, the display elements 60 of the same color are aligned in avertical direction of the drawing. Such a structure is preferablebecause the structure will make it easier to separately form colorfilters or light-emitting elements in accordance with colors of thedisplay elements.

FIG. 13A shows the case where one pixel includes the display elements 60of three colors. The outline of the display element 60 has a linearportion along a direction of the lattice of the electrode 31, and has arectangular shape with rounded corners. The display elements of the samecolor are aligned in the direction of the linear portion of the latticeof the electrode 31, which constitutes stripe arrangement. In each ofFIGS. 13B, 13C, and 13D, the electrode 31 has a different shape fromthat in FIG. 13A.

Note that marks such as R, G, B, and Y are given to some displayelements 60 in FIG. 10 to FIG. 13D to facilitate description; however,the arrangement method is just an example, and does not limit anarrangement method of the display elements 60. R, G, B, and Y can bereplaced with one another. In addition, W that corresponds to a displayelement of white may be provided in replacement of R, G, B, or Y.

The above is the description of the structure example of the pixel.

[Cross-Sectional Structure Example]

An example of a cross-sectional structure of the touch panel 100 isdescribed below with reference to drawings.

[Cross-Sectional Structure Example 1]

FIG. 14 is a schematic cross-sectional view of the touch panel 100. FIG.14 illustrates cross sections of a region including an FPC 73, a regionincluding the driver circuit 82, a region including the display portion81, and a region including the FPC 50 in FIG. 1A.

The substrate 71 and the substrate 72 are attached to each other with anadhesive layer 151. The substrate 72 and the substrate 30 are attachedto each other with an adhesive layer 152. Here, a structure includingthe substrate 71, the substrate 72, and components provided therebetweencorresponds to the display panel 70. A structure including the substrate30 and components provided on the substrate 30 corresponds to the inputdevice 10.

<Display Panel 70>

A transistor 201, a transistor 202, a transistor 203, the displayelement 60, a capacitor 205, a connection portion 206, a wiring 207, andthe like are provided between the substrates 71 and 72.

An insulating layer 211, an insulating layer 212, an insulating layer213, an insulating layer 214, an insulating layer 215, a spacer 216, andthe like are provided over the substrate 71. Part of the insulatinglayer 211 functions as a gate insulating layer of each transistor, andanother portion thereof functions as a dielectric of the capacitor 205.The insulating layer 212, the insulating layer 213, and the insulatinglayer 214 are provided to cover each transistor, the capacitor 205, andthe like. The insulating layer 214 functions as a planarization layer.Note that an example where the three insulating layers, the insulatinglayers 212, 213, and 214, are provided to cover the transistors and thelike is described here; however, the present invention is not limited tothis example, and four or more insulating layers, a single insulatinglayer, or two insulating layers may be provided. The insulating layer214 functioning as a planarization layer is not necessarily providedwhen not needed.

The display element 60 is provided over the insulating layer 214. Here,an example is shown where a top-emission type light-emitting element(organic EL element) is used as the display element 60. The displayelement 60 emits light toward a second electrode 223 side. When thetransistors 202 and 203, the capacitor 205, the wiring or the like areprovided to overlap with the light-emitting region of the displayelement 60, the aperture ratio of the display portion 81 can beincreased.

The display element 60 includes an EL layer 222 between a firstelectrode 221 and the second electrode 223. An optical adjustment layer224 is provided between the first electrode 221 and the EL layer 222.The insulating layer 215 is provided to cover end portions of the firstelectrode 221 and the optical adjustment layer 224.

FIG. 14 illustrates a cross section of one pixel as an example of thedisplay portion 81. An example where the pixel includes the transistor202 for current control, the transistor 203 for switching control, andthe capacitor 205 is described here. One of a source and a drain of thetransistor 202 and one electrode of the capacitor 205 are electricallyconnected to the first electrode 221 through an opening provided in theinsulating layers 212, 213, and 214.

FIG. 14 illustrates an example of the driver circuit 82 in which thetransistor 201 is provided.

Each of the transistors 201, 202 and 203 has a conductive layer 241functioning as a gate electrode, a semiconductor layer 242, a pair ofconductive layers 243, and an insulating layer 211 functioning as a gateinsulator. One of the conductive layers 243 functions as a sourceelectrode while the other of the conductive layers 243 functions as adrain electrode.

In the example illustrated in FIG. 14, the transistors 201 and 202 eachhave a structure in which a semiconductor layer where a channel isformed is provided between two gate electrodes (conductive layers 241and 244). Such transistors can have higher field-effect mobility andthus have higher on-state current than other transistors. Consequently,a circuit capable of high-speed operation can be obtained. Furthermore,the area occupied by a circuit can be reduced. The use of the transistorhaving high on-state current can reduce signal delay in wirings and canreduce display luminance variation even in a display panel in which thenumber of wirings is increased because of increase in size orresolution.

Note that the transistors provided in the driver circuit 82 and thedisplay portion 81 may have the same structure or different structures.

A material through which impurities such as water or hydrogen do noteasily diffuse is preferably used for at least one of the insulatinglayers 212 and 213 which cover the transistors. That is, the insulatinglayer 212 or the insulating layer 213 can function as a barrier film.Such a structure can effectively suppress diffusion of the impuritiesinto the transistors from the outside, and a highly reliable touch panelcan be achieved.

The spacer 216 is provided over the insulating layer 215 and has afunction of adjusting the distance between the substrate 71 and thesubstrate 72. In the example illustrated in FIG. 14, there is a gapbetween the spacer 216 and a light-blocking layer 232, which may howeverbe in contact with each other. Although the spacer 216 is provided onthe substrate 71 side in the structure described here, the spacer 216may be provided on the substrate 72 side (e.g., in a position closer tothe substrate 71 than that of the light-blocking layer 232).Alternatively, a particulate spacer may be used instead of the spacer216. Although a material such as silica can be used for the particulatespacer, an elastic material such as an organic resin or rubber ispreferably used. In some cases, the particulate spacer may be verticallycrushed.

A coloring layer 231, the light-blocking layer 232, and the like areprovided on the substrate 71 side of the substrate 72. Thelight-blocking layer 232 has an opening, and the opening overlaps withthe display region of the display element 60. The coloring layer 231overlaps with the display element 60.

As examples of a material that can be used for the light-blocking layer232, carbon black, a metal oxide, and a composite oxide containing asolid solution of a plurality of metal oxides can be given. Stackedfilms containing the material of the coloring layer 231 can also be usedfor the light-blocking layer 232. For example, a material containing anacrylic resin can be used for the coloring layer 231, and astacked-layer structure of a film containing a material of a coloringlayer which transmits light of a certain color and a film containing amaterial of a coloring layer which transmits light of another color canbe employed. It is preferable that the coloring layer 231 and thelight-blocking layer 232 be formed using the same material because thesame manufacturing apparatus can be used and the process can besimplified.

As examples of a material that can be used for the coloring layer 231, ametal material, a resin material, and a resin material containing apigment or dye can be given.

An insulating layer which functions as an overcoat may be provided tocover the coloring layer 231 and the light-blocking layer 232.

The connection portion 206 is provided in a region near an end portionof the substrate 71. The connection portion 206 is electricallyconnected to the FPC 73 through a connection layer 209. In the exampleof the structure illustrated in FIG. 14, the connection portion 206 isformed by stacking part of the wiring 207 which is electricallyconnected to the driver circuit 82 and a conductive layer which isformed by processing a conductive film used for forming the firstelectrode 221. When the connection portion 206 is formed by stacking twoor more conductive layers as described above, electric resistance can bereduced and mechanical strength of the connection portion 206 can beincreased.

Furthermore, FIG. 14 illustrates a cross-sectional structure of anintersection portion 86 where a wiring formed by processing a conductivefilm used for forming the gate electrode of the transistor and a wiringformed by processing a conductive film used for forming a sourceelectrode and a drain electrode of the transistor intersect with eachother.

Here, the scan line 87 formed by processing a conductive film used forforming the gate electrode of the transistor is provided at theintersection portion 86. Note that the scan line 87 may be a wiringformed by processing a conductive film used for forming the sourceelectrode and the drain electrode of a transistor or another conductivefilm.

<Input Device 10>

The electrode 31 and the electrode 32 are provided on the substrate 72side of the substrate 30. An example where the electrode 31 includes theelectrode 33 and the bridge electrode 34 is described here. Asillustrated in the intersection portion 86 in FIG. 14, the electrode 32and the electrode 33 are formed in the same plane. The bridge electrode34 is provided over an insulating layer 161 which covers the electrode32 and the electrode 33. The bridge electrode 34 electrically connectstwo electrodes 33, between which the electrode 32 is provided, throughopenings formed in the insulating layer 161.

In the structure of FIG. 14, the electrode 33 does not overlap with thedisplay element 60. That is, the electrode 33 is provided such that anopening of the electrode 33 and the display element 60 overlap with eachother. Here, it is preferable that the electrode 33 not overlap with thecoloring layer 231. The electrode 33 preferably overlaps with thelight-blocking layer 232. Note that an example of the electrode 33 isshown here, but it is preferable that the electrodes 31 and 32 and thebridge electrode 34 also not overlap with the display element 60 or thelike.

A connection portion 106 is provided in a region near an end portion ofthe substrate 30. The connection portion 106 is electrically connectedto the FPC 50 through a connection layer 109. In the example of thestructure illustrated in FIG. 14, the connection portion 106 is formedby stacking part of the wiring 42 and a conductive layer which is formedby processing a conductive film used for forming the bridge electrode34.

As the connection layer 109 or the connection layer 209, an anisotropicconductive film (ACF), an anisotropic conductive paste (ACP), or thelike can be used.

The substrate 30 here can be used also as a substrate with which anobject to be sensed, such as a finger or a stylus, is to be in contact.In that case, a protective layer (such as a ceramic coat) is preferablyprovided over the substrate 30. The protective layer can be formed usingan inorganic insulating material such as silicon oxide, aluminum oxide,yttrium oxide, or yttria-stabilized zirconia (YSZ). Alternatively,tempered glass may be used for the substrate 30. The tempered glasswhich can be used here is one that has been subjected to physical orchemical treatment by an ion exchange method, a thermal temperingmethod, or the like and has a surface to which compressive stress hasbeen added. In the case where the touch sensor is provided on one sideof the tempered glass and the opposite side of the tempered glass isprovided on, for example, the outermost surface of an electronic devicefor use as a touch surface, the thickness of the whole device can bedecreased.

<Components>

The above-mentioned components are described below.

A substrate having a flat surface can be used as the substrate includedin the touch panel. The substrate on the side from which light from thedisplay element is extracted is formed using a material that transmitsthe light. For example, a material such as glass, quartz, ceramics,sapphire, or an organic resin can be used.

The weight and thickness of the touch panel can be decreased by using athin substrate. A flexible touch panel can be obtained by using asubstrate that is thin enough to have flexibility.

As the glass, for example, non-alkali glass, barium borosilicate glass,aluminoborosilicate glass, or the like can be used.

Examples of a material that has flexibility and transmits visible lightinclude flexible glass, polyester resins such as polyethyleneterephthalate (PET) and polyethylene naphthalate (PEN), apolyacrylonitrile resin, a polyimide resin, a polymethyl methacrylateresin, a polycarbonate (PC) resin, a polyethersulfone (PES) resin, apolyamide resin, a cycloolefin resin, a polystyrene resin, a polyamideimide resin, a polyvinyl chloride resin, and a polytetrafluoroethylene(PTFE). In particular, a material whose thermal expansion coefficient islow is preferable, and for example, a polyamide imide resin, a polyimideresin, or PET can be suitably used. A substrate in which a glass fiberis impregnated with an organic resin or a substrate whose thermalexpansion coefficient is reduced by mixing an organic resin with aninorganic filler can also be used. A substrate using such a material islightweight, and accordingly a touch panel using this substrate can alsobe lightweight.

Since it is not necessary for the substrate through which light emissionis not extracted to have a light-transmitting property, a metalsubstrate, a ceramic substrate, a semiconductor substrate, or the likecan be used as well as the above-described substrates. A metalsubstrate, which has high thermal conductivity, is preferable becausethey can easily conduct heat to the whole substrate and accordingly canprevent a local temperature rise in the touch panel. To obtainflexibility and bendability, the thickness of a metal substrate ispreferably greater than or equal to 10 μm and less than or equal to 200μm, more preferably greater than or equal to 20 μm and less than orequal to 50 μm.

Although there is no particular limitation on a material of a metalsubstrate, it is favorable to use, for example, a metal such asaluminum, copper, and nickel, an aluminum alloy, or an alloy such asstainless steel.

It is preferable to use a substrate subjected to insulation treatment,e.g., a metal substrate whose surface is oxidized or provided with aninsulating film. An insulating film may be formed by, for example, acoating method such as a spin-coating method and a dipping method, anelectrodeposition method, an evaporation method, or a sputtering method.An oxide film may be formed over the substrate surface by a known methodsuch as an anodic oxidation method, exposing to or heating in an oxygenatmosphere, or the like.

A hard coat layer (e.g., a silicon nitride layer) by which a touch panelsurface is protected from damage, a layer (e.g., an aramid resin layer)that can disperse pressure, or the like may be stacked over the flexiblesubstrate. Furthermore, to suppress a decrease in lifetime of thedisplay element due to water and the like, an insulating film with lowwater permeability may be provided to the flexible substrate. Forexample, a film containing nitrogen and silicon (e.g., a silicon nitridefilm, a silicon oxynitride film), or a film containing nitrogen andaluminum (e.g., an aluminum nitride film) may be provided.

The substrate may be formed by stacking a plurality of layers. When aglass layer is used, a barrier property against water and oxygen can beimproved and thus a highly reliable touch panel can be provided.

A substrate in which a glass layer, an adhesive layer, and an organicresin layer are stacked from the side closer to the display element canbe used, for example. The thickness of the glass layer is greater thanor equal to 20 μm and less than or equal to 200 μm, preferably greaterthan or equal to 25 μm and less than or equal to 100 μm. With such athickness, the glass layer can have both a high barrier property againstwater and oxygen and a high flexibility. The thickness of the organicresin layer is greater than or equal to 10 μm and less than or equal to200 μm, preferably greater than or equal to 20 μm and less than or equalto 50 μm. Providing such an organic resin layer outside the glass layer,occurrence of a crack or a break in the glass layer can be suppressedand mechanical strength can be improved. With the substrate thatincludes such a composite material of a glass material and an organicresin, a highly reliable flexible touch panel can be provided.

The transistor includes a conductive layer functioning as the gateelectrode, the semiconductor layer, a conductive layer functioning asthe source electrode, a conductive layer functioning as the drainelectrode, and an insulating layer functioning as the gate insulatinglayer.

Note that there is no particular limitation on the structure of thetransistor included in the touch panel of one embodiment of the presentinvention. For example, a forward staggered transistor or an invertedstaggered transistor may be used. A top-gate transistor or a bottom-gatetransistor may be used. There is no particular limitation on asemiconductor material that is used for the transistors, and forexample, an oxide semiconductor, silicon, germanium, or an organicsemiconductor can be used.

There is no particular limitation on the crystallinity of asemiconductor material used for the transistors, and an amorphoussemiconductor or a semiconductor having crystallinity (amicrocrystalline semiconductor, a polycrystalline semiconductor, asingle-crystal semiconductor, or a semiconductor partly includingcrystal regions) may be used. It is preferable that a semiconductorhaving crystallinity be used, in which case deterioration of thetransistor characteristics can be suppressed.

As a semiconductor material for the semiconductor layer of thetransistor, an element of Group 14, a compound semiconductor, or anoxide semiconductor can be used, for example. Typically, a semiconductorcontaining silicon, a semiconductor containing gallium arsenide, anoxide semiconductor containing indium, or the like can be used.

An oxide semiconductor is preferably used as a semiconductor in whichthe channel of the transistor is formed. In particular, an oxidesemiconductor having a wider band gap than silicon is preferably used. Asemiconductor material having a wider band gap and a lower carrierdensity than silicon is preferably used because off-state leakagecurrent of the transistor can be reduced.

For example, at least indium (In) or zinc (Zn) is preferably included asthe oxide semiconductor. More preferably, an In-M-Zn-based oxide (M is ametal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf) is included.

As the semiconductor layer, it is particularly preferable to use anoxide semiconductor film including a plurality of crystal parts whosec-axes are aligned substantially perpendicular to a surface on which thesemiconductor layer is formed or the top surface of the semiconductorlayer and in which a grain boundary is not observed between adjacentcrystal parts.

There is no grain boundary in such an oxide semiconductor; therefore,generation of a crack in an oxide semiconductor film which is caused bystress when a display panel is bent is prevented. Therefore, such anoxide semiconductor can be preferably used for a flexible touch panelwhich is used in a bent state, or the like.

Moreover, the use of such an oxide semiconductor with crystallinity forthe semiconductor layer makes it possible to provide a highly reliabletransistor in which a change in the electrical characteristics issuppressed.

A transistor with an oxide semiconductor whose band gap is larger thanthe band gap of silicon can hold charges stored in a capacitor that isseries-connected to the transistor for a long time, owing to the lowoff-state current of the transistor. When such a transistor is used fora pixel, operation of a driver circuit can be stopped while a gray scaleof an image displayed in each display region is maintained. As a result,a display device with extremely low power consumption can be obtained.

Alternatively, silicon is preferably used as a semiconductor in whichthe channel of the transistor is formed. Although amorphous silicon maybe used as silicon, silicon having crystallinity is particularlypreferable. For example, microcrystalline silicon, polycrystallinesilicon, single-crystal silicon, or the like is preferably used. Inparticular, polycrystalline silicon can be formed at a lower temperaturethan single-crystal silicon and has higher field effect mobility andhigher reliability than amorphous silicon. When such a polycrystallinesemiconductor is used for a pixel, the aperture ratio of the pixel canbe improved. Even in the case where pixels are provided at extremelyhigh resolution, a scan line driver circuit and a signal line drivercircuit can be formed over a substrate over which the pixels are formed,and the number of components of an electronic device can be reduced.

As a gate, a source, and a drain of a transistor, and a wiring or anelectrode included in a touch panel, any of metals such as aluminum,titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum,silver, tantalum, and tungsten, or an alloy containing any of thesemetals as its main component can be used. A single-layer structure ormulti-layer structure including a film containing any of these materialscan be used. For example, the following structures can be given: asingle-layer structure of an aluminum film containing silicon, atwo-layer structure in which an aluminum film is stacked over a titaniumfilm, a two-layer structure in which an aluminum film is stacked over atungsten film, a two-layer structure in which a copper film is stackedover a copper-magnesium-aluminum alloy film, a two-layer structure inwhich a copper film is stacked over a titanium film, a two-layerstructure in which a copper film is stacked over a tungsten film, athree-layer structure in which a titanium film or a titanium nitridefilm, an aluminum film or a copper film, and a titanium film or atitanium nitride film are stacked in this order, and a three-layerstructure in which a molybdenum film or a molybdenum nitride film, analuminum film or a copper film, and a molybdenum film or a molybdenumnitride film are stacked in this order. Note that a transparentconductive material containing indium oxide, tin oxide, or zinc oxidemay be used. Copper containing manganese is preferably used becausecontrollability of a shape by etching is increased.

As a light-transmitting material that can be used for conductive layerssuch as wirings and electrodes in the touch panel, a conductive oxidesuch as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide,or zinc oxide to which gallium is added, or graphene can be used.Alternatively, a metal material such as gold, silver, platinum,magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper,palladium, or titanium, or an alloy material containing any of thesemetal materials can be used. Alternatively, a nitride of the metalmaterial (e.g., titanium nitride) or the like may be used. In the caseof using the metal material or the alloy material (or the nitridethereof), the thickness is set small enough to be able to transmitlight. Alternatively, a stack of any of the above materials can be usedas the conductive layer. For example, a stacked film of indium tin oxideand an alloy of silver and magnesium is preferably used because theconductivity can be increased.

Examples of an insulating material that can be used for the insulatinglayers, the overcoat, the spacer, and the like include a resin such asacrylic or epoxy resin, a resin having a siloxane bond, and an inorganicinsulating material such as silicon oxide, silicon oxynitride, siliconnitride oxide, silicon nitride, or aluminum oxide.

The light-emitting element is preferably provided between a pair ofinsulating films with low water permeability, in which case impuritiessuch as water can be prevented from entering the light-emitting element.Thus, a decrease in device reliability can be prevented.

As an insulating film with low water permeability, a film containingnitrogen and silicon (e.g., a silicon nitride film or a silicon nitrideoxide film), a film containing nitrogen and aluminum (e.g., an aluminumnitride film), or the like can be used. Alternatively, a silicon oxidefilm, a silicon oxynitride film, an aluminum oxide film, or the like canbe used.

For example, the water vapor transmittance of the insulating film withlow water permeability is lower than or equal to 1×10⁻⁵ [g/(m²·day)],preferably lower than or equal to 1×10⁻⁶ [g/(m²·day)], furtherpreferably lower than or equal to 1×10⁻⁷ [g/(m²·day)], still furtherpreferably lower than or equal to 1×10⁻⁸ [g/(m²·day)].

As the adhesive layers, a variety of curable adhesives such as areactive curable adhesive, a thermosetting adhesive, an anaerobicadhesive, and a photo curable adhesive such as an ultraviolet curableadhesive can be used. Examples of these adhesives include an epoxyresin, an acrylic resin, a silicone resin, a phenol resin, a polyimideresin, an imide resin, a polyvinyl chloride (PVC) resin, a polyvinylbutyral (PVB) resin, and an ethylene vinyl acetate (EVA) resin. Inparticular, a material with low water permeability, such as an epoxyresin, is preferable. Alternatively, a two-component-mixture-type resinmay be used. Further alternatively, an adhesive sheet or the like may beused.

Further, the resin may include a drying agent. For example, a substancethat adsorbs water by chemical adsorption, such as oxide of an alkalineearth metal (e.g., calcium oxide or barium oxide), can be used.Alternatively, a substance that adsorbs water by physical adsorption,such as zeolite or silica gel, may be used. The drying agent ispreferably included because it can prevent impurities such as water fromentering the functional element, thereby improving the reliability ofthe display panel.

In addition, it is preferable to mix a filler with a high refractiveindex or light-scattering member into the resin, in which case theefficiency of light extraction from the light-emitting element can beimproved. For example, titanium oxide, barium oxide, zeolite, zirconium,or the like can be used.

As the light-emitting element, a self-luminous element can be used, andan element whose luminance is controlled by current or voltage isincluded in the category of the light-emitting element. For example, alight-emitting diode (LED), an organic EL element, an inorganic ELelement, or the like can be used.

The light-emitting element may be a top emission, bottom emission, ordual emission light-emitting element. A conductive film that transmitsvisible light is used as the electrode through which light is extracted.A conductive film that reflects visible light is preferably used as theelectrode through which light is not extracted.

The EL layer includes at least a light-emitting layer. In addition tothe light-emitting layer, the EL layer may further include one or morelayers containing any of a substance with a high hole-injectionproperty, a substance with a high hole-transport property, ahole-blocking material, a substance with a high electron-transportproperty, a substance with a high electron-injection property, asubstance with a bipolar property (a substance with a high electron- andhole-transport property), and the like.

Either a low molecular compound or a high molecular compound can be usedfor the EL layer, and an inorganic compound may also be used. The layersincluded in the EL layer can be formed by any of the following methods:an evaporation method (including a vacuum evaporation method), atransfer method, a printing method, an inkjet method, a coating method,and the like.

When a voltage higher than the threshold voltage of the light-emittingelement is applied between the anode and the cathode, holes are injectedto the EL layer from the anode side and electrons are injected to the ELlayer from the cathode side. The injected electrons and holes arerecombined in the EL layer, so that a light-emitting substance containedin the EL layer emits light.

In the case where a light-emitting element emitting white light is usedas the light-emitting element, the EL layer preferably contains two ormore kinds of light-emitting substances. For example, light-emittingsubstances are selected so that two or more light-emitting substancesemit complementary colors to obtain white light emission. Specifically,it is preferable to contain two or more light-emitting substancesselected from light-emitting substances emitting light of red (R), green(G), blue (B), yellow (Y), orange (0), and the like and light-emittingsubstances emitting light containing two or more of spectral componentsof R, G, and B. The light-emitting element preferably emits light with aspectrum having two or more peaks in the wavelength range of a visiblelight region (e.g., 350 nm to 750 nm). An emission spectrum of amaterial emitting light having a peak in the wavelength range of ayellow light preferably includes spectral components also in thewavelength range of a green light and a red light.

A light-emitting layer containing a light-emitting material emittinglight of one color and a light-emitting layer containing alight-emitting material emitting light of another color are preferablystacked in the EL layer. For example, the plurality of light-emittinglayers in the EL layer may be stacked in contact with each other or maybe stacked with a separation layer therebetween. For example, between afluorescent layer and a phosphorescent layer, a region containing thesame material as one in the fluorescent layer or phosphorescent layer(for example, a host material or an assist material) and nolight-emitting element may be provided. This facilitates the manufactureof the light-emitting element and reduces the drive voltage.

The conductive film that transmits visible light can be formed using,for example, indium oxide, indium tin oxide (ITO), indium zinc oxide,zinc oxide, or zinc oxide to which gallium is added. Alternatively, afilm of a metal material such as gold, silver, platinum, magnesium,nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium,or titanium; an alloy containing any of these metal materials; or anitride of any of these metal materials (e.g., titanium nitride) can beused when formed thin so as to have a light-transmitting property.Alternatively, a stack of any of the above materials can be used as theconductive layer. For example, a stacked film of ITO and an alloy ofsilver and magnesium is preferably used, in which case conductivity canbe increased. Further alternatively, graphene or the like may be used.

For the conductive film that reflects visible light, for example, ametal material, such as aluminum, gold, platinum, silver, nickel,tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium or analloy including any of these metal materials can be used. Lanthanum,neodymium, germanium, or the like may be added to the metal material orthe alloy. Furthermore, an alloy containing aluminum (an aluminum alloy)such as an alloy of aluminum and titanium, an alloy of aluminum andnickel, or an alloy of aluminum and neodymium; or an alloy containingsilver such as an alloy of silver and copper, an alloy of silver,copper, and palladium, or an alloy of silver and magnesium can be usedfor the conductive film. An alloy of silver and copper is preferablebecause of its high heat resistance. Moreover, a metal film or a metaloxide film is stacked on an aluminum alloy film, whereby oxidation ofthe aluminum alloy film can be suppressed. Examples of a material forthe metal film or the metal oxide film are titanium and titanium oxide.Alternatively, the conductive film having a property of transmittingvisible light and a film containing any of the above metal materials maybe stacked. For example, a stacked film of silver and ITO or a stackedfilm of an alloy of silver and magnesium and ITO can be used.

The conductive film may be formed separately by an evaporation method ora sputtering method. Alternatively, a discharging method such as anink-jet method, a printing method such as a screen printing method, or aplating method may be used.

The light-emitting element may be a single element including one ELlayer or a tandem element in which a plurality of EL layers are stackedwith a charge generation layer therebetween.

The above is the descriptions of the components.

Structure examples which partly differ from the above cross-sectionalstructure example 1 will be described below with reference to drawings.Note that descriptions of the portions already described are omitted anddifferent portions are described below.

[Cross-Sectional Structure Example 2]

FIG. 15 illustrates a cross-sectional structure example of the touchpanel 100 which partly differs from the structure of FIG. 14.

In FIG. 15, in the transistors 201 and 202, conductive layersfunctioning as the second gates are provided between the insulatinglayer 213 and the insulating layer 214. Such a structure is preferablebecause the voltage to be applied to the second gates can be lowered ascompared with the structure in FIG. 14.

FIG. 15 illustrates an example where the display element 60 is formed bya separate coloring method. Specifically, pixels of different colorsinclude different EL layers 222 which emit light of the respectivecolors. In a region outside the light-emitting region of the displayelement 60, an end portion of the EL layer 222 is covered with thesecond electrode 223. The EL layer 222 can be formed by, for example, anevaporation method using a metal mask, a printing method, an inkjetmethod, or the like.

In the example illustrated in FIG. 15, the optical adjustment layer 224and the coloring layer 231 illustrated in FIG. 14 are not provided.

FIG. 15 shows an example where a protection film 217 is provided tocover the second electrode 223. The protection film 217 serves as abarrier film that prevents impurities such as water from diffusing intothe display element 60. Although not illustrated in the drawing, an endportion of the EL layer 222 or an end portion of the second electrode223 is covered with the protection film 217, whereby entry of water intothe display element 60 can be more effectively inhibited.

As the protection film 217, an organic insulation material or aninorganic insulation material can be used. An inorganic insulationmaterial is preferably used because a film with a high barrier propertycan be formed to be thin. When an inorganic insulation material is usedas the protection film 217, silicon nitride, silicon nitride oxide,aluminum oxide, aluminum oxynitride, aluminum nitride oxide, aluminumnitride, hafnium oxide, or the like is preferably used. Aluminum oxideis particularly preferable because of its excellent barrier property. Asa deposition method of the protection film 217, a sputtering method, anevaporation method, a chemical vapor deposition (CVD) method, an atomiclayer deposition (ALD) method, or the like can be used. The ALD methodis particularly preferable to inhibit damage to the display element 60at the time of deposition. Although a thermal ALD method can be used asthe ALD method, a plasma enhanced ALD (PEALD) method is more preferablebecause a film can be formed at low temperatures around roomtemperature.

Note that the structures of the transistors, the display elements 60,the protection film 217, and the like can be replaced with those of thetransistors, the display elements and the like shown in FIG. 14 andcross-sectional structures described below.

[Cross-Sectional Structure Example 3]

A touch panel illustrated in FIG. 16 includes a substrate 111 and asubstrate 112. The substrate 111 and the substrate 72 are attached toeach other with the adhesive layer 152, and the substrate 111 and thesubstrate 112 are attached to each other with an adhesive layer 153.

The substrate 111 is provided with the electrode 32, the wiring 42, andthe like. The substrate 112 is provided with the electrode 31, thewiring 41 (not illustrated), and the like. In FIG. 16, the FPC 50 isprovided for the substrate 111; the substrate 112 is similarly providedwith an FPC in a region not illustrated in the drawing.

In the case where two substrates are used in the structure of the inputdevice 10 as described above, substrates as thin as, or thinner than,the substrates 71 and 72 are preferably used as the substrates 111 and112. In particular, the material having flexibility described above ispreferably used for the substrates 111 and 112, in which case thethickness of the touch panel 100 can be decreased.

A protective substrate 130 may be provided over the substrate 112 withan adhesive layer 154 therebetween as illustrated in FIG. 16. A surfaceof the protective substrate 130 on a side opposite to the substrate 112side functions as a touch surface. The above description of thesubstrate 30 can be referred to for a material of the protectivesubstrate 130.

[Cross-Sectional Structure Example 4]

A touch panel shown in FIG. 17 includes a substrate 113. The substrates113 and 72 are attached to each other with the adhesive layer 152.

The substrate 113 is provided with the electrode 32, the wiring 42, andthe like on one side. The substrate 113 is also provided with theelectrode 31, the wiring 41, and the like on the other side. That is,the electrodes and wirings in the touch sensor are provided on bothsides of the substrate 113.

FIG. 17 illustrates an example in which an FPC 50 a and a connectionlayer 109 a are provided in a connection portion 106 a where part of thewiring 42 is exposed, and an FPC 50 b and a connection layer 109 b areprovided in a connection portion 106 b where part of the wiring 41 isexposed. Note that the connection portion 106 a and the connectionportion 106 b may overlap with each other in a plan view, or may bearranged so as not to overlap with each other.

[Cross-Sectional Structure Example 5]

In a touch panel illustrated in FIG. 18, the electrodes and the like ofthe touch sensor are provided over a surface of the substrate 72 that isopposite to a surface facing the substrate 71. Specifically, thesubstrate 72 is provided with the bridge electrode 34, and theinsulating layer 161 covering part of the bridge electrode 34; and theelectrode 31, the electrode 32, the wiring 41 (not illustrated), thewiring 42, and the like are over the insulating layer 161.

As illustrated in FIG. 18, the protective substrate 130 and thesubstrate 72 may be attached to each other with the adhesive layer 152.

In this structure, the input device 10 and the display panel 70 canshare the substrate; thus, the thickness of the touch panel can besignificantly decreased.

[Cross-Sectional Structure Example 6]

FIG. 19 illustrates an example in which the structure of the touchsensor illustrated in FIG. 18 is combined with the structure of thetouch panel illustrated in FIG. 15 where the light-emitting elementformed by a separate coloring method is used as the display element 60.In the example illustrated in FIG. 19, the light-blocking layer 232 isnot provided.

[Cross-Sectional Structure Example 7]

In a touch panel illustrated in FIG. 20, the electrodes and the like ofthe touch sensor are provided on the substrate 71 side of the substrate72. Specifically, the substrate 72 is provided with the electrode 32,the electrode 33, the wiring 41 (not illustrated), the wiring 42, theinsulating layer 161 covering these components, and the bridge electrode34 over the insulating layer 161, and the like.

An insulating layer 233 is provided to cover the electrodes and the likein the touch sensor. In addition, the coloring layer 231, thelight-blocking layer 232, and the like are provided over the insulatinglayer 233.

In this structure, the input device 10 and the display panel 70 canshare the substrate and one surface of the substrate 72 can be used as atouch surface; thus, the thickness of the touch panel 100 can be furtherdecreased.

[Cross-Sectional Structure Example 8]

FIG. 21 illustrates a modification example of the touch panel shown inFIG. 20.

The touch panel in FIG. 21 has a stacked-layer structure including asubstrate 91, an adhesive layer 92, a substrate 93, and an insulatinglayer 94 in place of the substrate 71. The touch panel also has astacked-layer structure including a substrate 191, an adhesive layer192, a substrate 193, and an insulating layer 194 in place of thesubstrate 72.

A material through which impurities such as water or hydrogen do noteasily diffuse can be used for the insulating layer 94 and theinsulating layer 194. Such a structure can effectively suppressdiffusion of the impurities into the display element 60 and thetransistors even in the case of using a material permeable to water forthe substrate 91, the substrate 93, the substrate 191, and the substrate193, and a highly reliable touch panel can be achieved.

A material such as a resin having flexibility can be used for thesubstrate 93 and the substrate 193. Films having flexibility or the likeare preferably used as the substrate 91 and the substrate 191. With theuse of a material having flexibility for these substrates, a bendabletouch panel can be achieved.

[Cross-Sectional Structure Example 9]

In a touch panel illustrated in FIG. 22, the light-blocking layer 232 isprovided between the electrodes and the like of the touch sensor and thesubstrate 72. Specifically, the substrate 72 is provided with thelight-blocking layer 232, and an insulating layer 234 is formed to coverthe light-blocking layer 232. The electrode 32, the electrode 33, thewiring 41 (not illustrated), the wiring 42, the insulating layer 161covering these components, and the bridge electrode 34 riding theinsulating layer 161, and the like are provided for an insulating layer234. In addition, the insulating layer 233 is formed to ride the bridgeelectrode 34 and the insulating layer 161, and the coloring layer 231 isformed to ride the insulating layer 233, and the like.

The insulating layers 233 and 234 have a function as a planarizationfilm. Note that the insulating layer 233 and 234 are not necessarilyprovided when not needed.

With such a structure, the light-blocking layer 232 provided in aposition closer to the viewing side than the electrodes and the like ofthe touch sensor is can prevent external light from being reflected bythe electrodes and the like, and prevent the electrodes and the likefrom being visible. Thus, a touch panel with not only small thicknessbut also improved visibility can be achieved.

[Cross-Sectional Structure Example 10]

FIG. 23 illustrates a modification example of the touch panelillustrated in FIG. 22.

The touch panel in FIG. 23 has a stacked-layer structure including thesubstrate 91, the adhesive layer 92, and the insulating layer 94 inplace of the substrate 71. The touch panel also has a stacked-layerstructure including the substrate 191, the adhesive layer 192, and theinsulating layer 194 in place of the substrate 72.

With the use of a material having flexibility for the substrates 91 and191, a bendable touch panel can be achieved.

[Cross-Sectional Structure Example 11]

FIG. 24 illustrates a cross-sectional structure example of a touch panelwhere a liquid crystal display device is used as the display panel 70.In the touch panel illustrated in FIG. 24, a liquid crystal element isused as a display element 208. The touch panel includes a polarizingplate 131, a polarizing plate 132, and a backlight 133.

In the example illustrated here, a liquid crystal element using a fringefield switching (FFS) mode is used as the display element 208. Thedisplay element 208 includes an electrode 251, an electrode 252, and aliquid crystal 253. The electrode 251 is provided over the electrode 252with an insulating layer 254 provided therebetween, and has a comb-likeshape or a shape provided with a slit.

An overcoat 255 is provided to cover the coloring layer 231 and thelight-blocking layer 232. The overcoat 255 has a function of preventinga pigment or the like which is included in the coloring layer 231 or thelight-blocking layer 232 from diffusing into the liquid crystal 253.

Surfaces of the overcoat 255, the insulating layer 254, the electrode251, and the like which are in contact with the liquid crystal 253 maybe provided with alignment films for controlling the orientation of theliquid crystal 253.

In FIG. 24, the polarizing plate 131 is attached to the substrate 71with an adhesive layer 157. The backlight 133 is attached to thepolarizing plate 131 with an adhesive layer 158. The polarizing plate132 is positioned between the substrate 72 and the substrate 30. Thepolarizing plate 132 is attached to the substrate 72 with an adhesivelayer 155, and is attached to the substrate 30 (specifically, part ofthe insulating layer 161 provided with the substrate 30) with anadhesive layer 156.

Although the liquid crystal element using an FFS mode is describedabove, a vertical alignment (VA) mode, a twisted nematic (TN) mode, anin-plane-switching (IPS) mode, an axially symmetric aligned micro-cell(ASM) mode, an optically compensated birefringence (OCB) mode, aferroelectric liquid crystal (FLC) mode, an antiferroelectric liquidcrystal (AFLC) mode, or the like can be used.

As the liquid crystal, a thermotropic liquid crystal, a low-molecularliquid crystal, a high-molecular liquid crystal, a ferroelectric liquidcrystal, an anti-ferroelectric liquid crystal, a polymer dispersedliquid crystal (PDLC), or the like can be used. Moreover, a liquidcrystal exhibiting a blue phase is preferably used because an alignmentfilm is not needed and a wide viewing angle is obtained in that case.

[Cross-Sectional Structure Example 12]

FIG. 25 illustrates a cross-sectional structure example of a touch panelwhere a liquid crystal display device is used as the display panel 70.In the touch panel illustrated in FIG. 25, the polarizing plate 132 isprovided in a position closer to the viewing side than that of theelectrodes and the like in the touch sensor. Specifically, a substrate114 provided with the electrode 31, the electrode 32, and the like isattached to the substrate 72 with the adhesive layer 152, and thepolarizing plate 132 is attached to the substrate 114 with the adhesivelayer 155. The protective substrate 130 attached to the polarizing plate132 with the adhesive layer 156 is provided in a position closer to theviewing side than that of the polarizing plate 132.

A film having flexibility or the like is preferably used as thesubstrate 114 because the thickness of the touch panel can be decreased.

[Cross-Sectional Structure Example 13]

FIG. 26 illustrates a cross-sectional structure example of a touch panelwhere a liquid crystal display device is used as the display panel. Inthe example of the touch panel illustrated in FIG. 26, the electrodesand the like of the touch sensor are formed on the substrate 71 side ofthe substrate 72. Specifically, the substrate 72 is provided with theelectrode 32, the electrode 33, the wiring 41 (not illustrated), thewiring 42, the insulating layer 161 covering these components, and thebridge electrode 34 riding the insulating layer 161, and the like. Theinsulating layer 233 is formed to cover the electrodes and the like ofthe touch sensor. In addition, the coloring layer 231, thelight-blocking layer 232, and the like are formed over the insulatinglayer 233.

The polarizing plate 132 is attached to the opposite side of thesubstrate 72 with the adhesive layer 155. The protective substrate 130is attached to the polarizing plate 132 with the adhesive layer 156.

In this structure, the input device and the display panel can share thesubstrate and one surface of the substrate 72 can be used as a touchsurface; thus, the thickness of the touch panel can be furtherdecreased.

[Cross-Sectional Structure Example 14]

FIG. 27 illustrates a cross-sectional structure example of a touch panelwhere a liquid crystal display device is used as the display panel. Inthe example of the touch panel illustrated in FIG. 27, the electrodesand the like of the touch sensor are provided on a side of the substrate72 opposite to the substrate 71 side. Specifically, the bridge electrode34 is formed over a surface of the substrate 72 on a side opposite tothe side where the coloring layer 231 and the like are provided; theinsulating layer 161 is formed to cover part of the bridge electrode 34;and the electrode 31, the electrode 32, the wiring 41 (not illustrated),the wiring 42, and the like are formed over the insulating layer 161.The polarizing plate 132 is attached to the substrate 72 with theadhesive layer 152, and the protective substrate 130 is attached to thepolarizing plate 132 with the adhesive layer 156.

The above is the description of the cross-sectional structure examples.

[Example of Manufacturing Method]

Here, a method for manufacturing a flexible touch panel is described.

For convenience, a structure including a pixel and a circuit, astructure including an optical member such as a color filter, astructure including an electrode or a wiring of a touch sensor, or thelike is referred to as an element layer. An element layer includes adisplay element, for example, and may include a wiring electricallyconnected to a display element or an element such as a transistor usedin a pixel or a circuit in addition to the display element.

Here, a support body (e.g., the substrate 91 or the substrate 191 inFIG. 23) with an insulating surface where an element layer is formed isreferred to as a substrate.

As a method for forming an element layer over a flexible substrateprovided with an insulating surface, there are a method in which anelement layer is formed directly over a substrate, and a method in whichan element layer is formed over a supporting base material that hasstiffness and then the element layer is separated from the supportingbase material and transferred to the substrate.

In the case where a material of the substrate can withstand heatingtemperature in a process for forming the element layer, it is preferablethat the element layer be formed directly over the substrate, in whichcase a manufacturing process can be simplified. At this time, theelement layer is preferably formed in a state where the substrate isfixed to a supporting base material, in which case transfer thereof inan apparatus and between apparatuses can be easy.

In the case of employing the method in which the element layer is formedover the supporting base material and then transferred to the substrate,first, a separation layer and an insulating layer are stacked over thesupporting base material, and then the element layer is formed over theinsulating layer. Next, the element layer is separated from thesupporting base material and then transferred to the substrate. At thistime, selected is a material with which separation at an interfacebetween the supporting base material and the separation layer, at aninterface between the separation layer and the insulating layer, or inthe separation layer occurs.

For example, it is preferable that a stacked layer of a layer includinga high-melting-point metal material, such as tungsten, and a layerincluding an oxide of the metal material be used as the insulating layeras the separation layer, and a stacked layer of a plurality of layers,such as a silicon nitride layer and a silicon oxynitride layer be usedas the insulating layer over the separation layer. The use of thehigh-melting-point metal material is preferable because the degree offreedom of the process for forming the element layer can be increased.

The separation may be performed by application of mechanical power, byetching of the separation layer, by dripping of a liquid into part ofthe separation interface to penetrate the entire separation interface,or the like. Alternatively, separation may be performed by heating theseparation interface by utilizing a difference in thermal expansioncoefficient.

The separation layer is not necessarily provided in the case whereseparation can occur at an interface between the supporting basematerial and the insulating layer. For example, glass and an organicresin such as polyimide may be used as the supporting base material andthe insulating layer, respectively, and a separation trigger may beformed by locally heating part of the organic resin by laser light orthe like, so that separation may be performed at an interface betweenthe glass and the insulating layer. Alternatively, a metal layer may beprovided between the supporting base material and the insulating layerformed of an organic resin, and separation may be performed at theinterface between the metal layer and the insulating layer formed of anorganic resin by heating the metal layer by feeding current to the metallayer. A layer of a light-absorbing material (e.g., a metal, asemiconductor, or an insulator) may be provided between the supportingbase layer and the insulating layer formed of an organic resin andlocally heated with laser light or the like to form a separationtrigger. In these methods, the insulating layer formed of an organicresin can be used as a substrate.

Examples of such a substrate having flexibility include polyester resinssuch as polyethylene terephthalate (PET) and polyethylene naphthalate(PEN), a polyacrylonitrile resin, a polyimide resin, a polymethylmethacrylate resin, a polycarbonate (PC) resin, a polyethersulfone (PES)resin, a polyamide resin, a cycloolefin resin, a polystyrene resin, apolyamide imide resin, and a polyvinyl chloride resin. In particular, amaterial whose thermal expansion coefficient is low, for example, lowerthan or equal to 30×10⁻⁶/K is preferable, and a polyamide imide resin, apolyimide resin, or PET can be suitably used. A substrate in which afibrous body is impregnated with a resin (also referred to as prepreg)or a substrate whose thermal expansion coefficient is reduced by mixingan inorganic filler with an organic resin can also be used.

In the case where a fibrous body is included in the above material, ahigh-strength fiber of an organic compound or an inorganic compound isused as the fibrous body. The high-strength fiber is specifically afiber with a high tensile elastic modulus or a fiber with a high Young'smodulus. Typical examples thereof include a polyvinyl alcohol basedfiber, a polyester based fiber, a polyamide based fiber, a polyethylenebased fiber, an aramid based fiber, a polyparaphenylene benzobisoxazolefiber, a glass fiber, and a carbon fiber. As the glass fiber, glassfiber using E glass, S glass, D glass, Q glass, or the like can be used.These fibers may be used in a state of a woven fabric or a nonwovenfabric, and a structure body in which this fibrous body is impregnatedwith a resin and the resin is cured may be used as the flexiblesubstrate. The structure body including the fibrous body and the resinis preferably used as the flexible substrate, in which case thereliability against bending or breaking due to local pressure can beincreased.

Alternatively, glass, metal, or the like that is thin enough to haveflexibility can be used as the substrate. Alternatively, a compositematerial where glass and a resin material are attached to each other maybe used.

In the structure shown in FIG. 23, for example, a first separation layerand the insulating layer 94 are formed in this order over a firstsupporting base material, and then components over the first separationlayer and the insulating layer 94 are formed. Separately, a secondseparation layer and the insulating layer 194 are formed in this orderover a second supporting base material, and then upper components areformed. Next, the first supporting base material and the secondsupporting base material are attached to each other with the adhesivelayer 151. After that, separation at an interface between the secondseparation layer and the insulating layer 194 is conducted so that thesecond supporting base material and the second separation layer areremoved, and then the substrate 191 is attached to the insulating layer194 with the adhesive layer 192. Further, separation at an interfacebetween the first separation layer and the insulating layer 94 isconducted so that the first supporting base material and the firstseparation layer are removed, and then the substrate 91 is attached tothe insulating layer 94 with the adhesive layer 92. Note that eitherside may be subjected to separation and attachment first.

The above is the description of a manufacturing method of a flexibletouch panel.

Although a light-emitting element and a liquid crystal element are usedas a display element here, one embodiment of the present invention isnot limited thereto.

For example, a display element such as a micro electro mechanical system(MEMS) element or an electron-emissive element can be used in thedisplay device. Examples of MEMS display elements include a MEMS shutterdisplay element, an optical interference type MEMS display element, andthe like. A carbon nanotube may be used for the electron-emissiveelement. Alternatively, electronic paper may be used. As the electronicpaper, an element using a microcapsule method, an electrophoreticmethod, an electrowetting method, an Electronic Liquid Powder(registered trademark) method, or the like can be used.

At least part of this embodiment can be implemented in combination withany of the embodiments described in this specification as appropriate.

Embodiment 2

In this embodiment, examples of a driving method of an input device oran input/output device of one embodiment of the present invention aredescribed with reference to drawings.

[Example of Sensing Method of Sensor]

FIG. 28A is a block diagram illustrating the structure of a mutualcapacitive touch sensor. FIG. 28A illustrates a pulse voltage outputcircuit 601 and a current sensing circuit 602. Note that in FIG. 28A,six wirings X1 to X6 represent electrodes 621 to which a pulse voltageis applied, and six wirings Y1 to Y6 represent electrodes 622 that sensechanges in current. FIG. 28A also illustrates a capacitor 603 that isformed where electrodes 621 and 622 overlap with each other. Note thatfunctional replacement between the electrodes 621 and 622 is possible.

The pulse voltage output circuit 601 is a circuit for sequentiallyapplying a pulse voltage to the wirings X1 to X6. By application of apulse voltage to the wirings X1 to X6, an electric field is generatedbetween the electrodes 621 and 622 of the capacitor 603. When theelectric field between the electrodes is shielded, for example, a changeoccurs in mutual capacitance of the capacitor 603. The approach orcontact of an object can be sensed by utilizing this change.

The current sensing circuit 602 is a circuit for sensing changes incurrent flowing through the wirings Y1 to Y6 that are caused by thechange in capacitance in the capacitor 603. No change in current valueis sensed in the wirings Y1 to Y6 when there is no approach or contactof an object, whereas a decrease in current value is sensed whencapacitance is decreased owing to the approach or contact of an object.Note that an integrator circuit or the like is used for sensing ofcurrent values.

FIG. 28B is a timing chart showing input and output waveforms in themutual capacitive touch sensor illustrated in FIG. 28A. In FIG. 28B,detection of an object is performed in all the rows and columns in oneframe period. FIG. 28B shows a period when an object is not detected(not touched) and a period when an object is detected (touched). Sensedcurrent values of the wirings Y1 to Y6 are shown as waveforms of voltagevalues.

A pulse voltage is sequentially applied to the wirings X1 to X6, andwaveforms of the wirings Y1 to Y6 change in accordance with the pulsevoltage. When there is no proximity or contact of an object, thewaveforms of the wirings Y1 to Y6 change in accordance with changes inthe voltages of the wirings X1 to X6. The current value is decreased atthe point of approach or contact of the object and accordingly thewaveform of the voltage value changes.

By sensing a change in mutual capacitance in this manner, proximity orcontact of an object can be sensed.

It is preferable that the pulse voltage output circuit 601 and thecurrent sensing circuit 602 be mounted on a substrate in a housing of anelectronic appliance or on the touch panel in the form of an IC. In thecase where the touch panel has flexibility, parasitic capacitance mightbe increased in a bent portion of the touch panel, and the influence ofnoise might be increased. In view of this, it is preferable to use an ICto which a driving method less influenced by noise is applied. Forexample, it is preferable to use an IC to which a driving method capableof increasing a signal-noise ratio (S/N ratio) is applied.

Although FIG. 28A is a passive matrix type touch sensor in which onlythe capacitor 603 is provided at the intersection portion of wirings asa touch sensor, an active matrix type touch sensor including atransistor and a capacitor may be used. FIG. 29 is a sensor circuitincluded in an active matrix type touch sensor.

The sensor circuit includes the capacitor 603 and transistors 611, 612,and 613. A signal G2 is input to a gate of the transistor 613. A voltageVRES is applied to one of a source and a drain of the transistor 613,and one electrode of the capacitor 603 and a gate of the transistor 611are electrically connected to the other of the source and the drain ofthe transistor 613. One of a source and a drain of the transistor 611 iselectrically connected to one of a source and a drain of the transistor612, and a voltage VSS is applied to the other of the source and thedrain of the transistor 611. A signal G1 is input to a gate of thetransistor 612, and a wiring ML is electrically connected to the otherof the source and the drain of the transistor 612. The voltage VSS isapplied to the other electrode of the capacitor 603.

Next, the operation of the sensor circuit will be described. First, apotential for turning on the transistor 613 is supplied as the signalG2, and a potential with respect to the voltage VRES is thus applied tothe node n connected to the gate of the transistor 611. Then, apotential for turning off the transistor 613 is applied as the signalG2, whereby the potential of the node n is maintained.

Then, capacitance of the capacitor 603 changes owing to the approach orcontact of an object such as a finger, and accordingly the potential ofthe node n is changed from VRES.

In reading operation, a potential for turning on the transistor 612 issupplied as the signal G1. A current flowing through the transistor 611,that is, a current flowing through the wiring ML is changed inaccordance with the potential of the node n. By sensing this current,the approach or contact of an object can be detected.

It is preferable that the transistors 611, 612, and 613 each include anoxide semiconductor in a semiconductor layer where a channel is formed.In particular, by using an oxide semiconductor in a semiconductor layerwhere a channel of the transistor 613 is formed, the potential of thenode n can be held for a long time and the frequency of operation(refresh operation) of resupplying VRES to the node n can be reduced.

[Structure Example of in-Cell Touch Panel]

Although the examples where the electrodes in the touch sensor areformed over a substrate different from a substrate where the displayelement and the like are provided are described above, one or both ofthe pair of electrodes in the touch sensor may be formed over thesubstrate where the display element and the like are provided.

A structural example of a touch panel incorporating the touch sensorinto a display portion including a plurality of pixels is describedbelow. Here, an example where a liquid crystal element is used as adisplay element provided in the pixel is shown.

FIG. 30A is an equivalent circuit diagram of part of a pixel circuitprovided in the display portion of the touch panel in this structureexample.

Each pixel includes at least a transistor 3503 and a liquid crystalelement 3504. In addition, a gate of the transistor 3503 is electricallyconnected to a wiring 3501, and one of a source and a drain of thetransistor 3503 is electrically connected to a wiring 3502.

The pixel circuit includes a plurality of wirings extending in the Xdirection (e.g., a wiring 3510_1 and a wiring 3510_2) and a plurality ofwirings extending in the Y direction (e.g., a wiring 3511). Thesewirings are provided to intersect with each other, and capacitance isformed therebetween.

Among the pixels provided in the pixel circuit, electrodes on one sideof the liquid crystal elements of some pixels adjacent to each other areelectrically connected to each other to form one block. The block isclassified into two types: an island-shaped block (e.g., a block 3515_1or a block 3515_2) and a linear block (e.g., a block 3516) extending inthe Y direction. Note that only part of the pixel circuit is illustratedin FIGS. 30A and 30B, but actually, these two kinds of blocks arerepeatedly arranged in the X direction and the Y direction.

The wiring 3510_1 (or 3510_2) extending in the X direction iselectrically connected to the island-shaped block 3515_1 (or the block3515_2). Although not illustrated, the wiring 3510_1 extending in the Xdirection is electrically connected to a plurality of island-shapedblocks 3515_1 which are provided discontinuously along the X directionwith the linear blocks therebetween. Further, the wiring 3511 extendingin the Y direction is electrically connected to the linear block 3516.

FIG. 30B is an equivalent circuit diagram illustrating the connectionbetween a plurality of wirings 3510 extending in the X direction and theplurality of wirings 3511 extending in the Y direction. An input voltageor a common potential can be input to each of the wirings 3510 extendingin the X direction. Further, a ground potential can be input to each ofthe wirings 3511 extending in the Y direction, or the wirings 3511 canbe electrically connected to the sensing circuit.

Operation of the above-described touch panel is described with referenceto FIGS. 31A and 31B.

Here, one frame period is divided into a writing period and a sensingperiod. The writing period is a period in which image data is written toa pixel, and the wirings 3510 (also referred to as gate lines or scanlines) are sequentially selected. On the other hand, the sensing periodis a period in which sensing is performed by a touch sensor, and thewirings 3510 extending in the X direction are sequentially selected andan input voltage is input.

FIG. 31A is an equivalent circuit diagram in the writing period. In thewriting period, a common potential is input to both the wiring 3510extending in the X direction and the wiring 3511 extending in the Ydirection.

FIG. 31B is an equivalent circuit diagram at a certain point of time inthe sensing period. In the sensing period, each of the wirings 3511extending in the Y direction is electrically connected to the sensingcircuit. An input voltage is input to the wirings 3510 extending in theX direction which are selected, and a common potential is input to thewirings 3510 extending in the X direction which are not selected.

Note that the driving method described here can be applied to not onlyan in-cell touch panel but also the above-described touch panels, andcan be used in combination with the method described in the drivingmethod example.

It is preferable that a period in which an image is written and a periodin which sensing is performed by a touch sensor be separately providedas described above. Thus, a decrease in sensitivity of the touch sensorcaused by noise generated when data is written to a pixel can besuppressed.

Embodiment 3

In this embodiment, electronic devices and lighting devices of oneembodiment of the present invention will be described with reference todrawings.

Electronic devices and lighting devices can be manufactured by using theinput device, the display device, or the input/output device of oneembodiment of the present invention. Highly reliable electronic devicesand lighting devices with curved surfaces can be manufactured by usingthe input device, the display device, or the input/output device of oneembodiment of the present invention. In addition, flexible and highlyreliable electronic devices and lighting devices can be manufactured byusing the input device, the display device, or the input/output deviceof one embodiment of the present invention. Furthermore, electronicdevices and lighting devices including touch sensors with improveddetection sensitivity and sensing accuracy can be manufactured by usingthe input device or the input/output device of one embodiment of thepresent invention.

Examples of electronic devices include a television set (also referredto as a television or a television receiver), a monitor of a computer orthe like, a digital camera, a digital video camera, a digital photoframe, a mobile phone (also referred to as a mobile phone device), aportable game machine, a portable information terminal, an audioreproducing device, a large game machine such as a pinball machine, andthe like.

The electronic device or the lighting device of one embodiment of thepresent invention has flexibility and therefore can be incorporatedalong a curved inside/outside wall surface of a house or a building or acurved interior/exterior surface of a car.

Furthermore, the electronic device of one embodiment of the presentinvention may include a secondary battery. It is preferable that thesecondary battery be capable of being charged by contactless powertransmission.

As examples of the secondary battery, a lithium ion secondary batterysuch as a lithium polymer battery (lithium ion polymer battery) using agel electrolyte, a lithium ion battery, a nickel-hydride battery, anickel-cadmium battery, an organic radical battery, a lead-acid battery,an air secondary battery, a nickel-zinc battery, and a silver-zincbattery can be given.

The electronic device of one embodiment of the present invention mayinclude an antenna. When a signal is received by the antenna, theelectronic device can display an image, data, or the like on a displayportion. When the electronic device includes a secondary battery, theantenna may be used for contactless power transmission.

FIGS. 32A, 32B, 32C1, 32C2, 32D, and 32E illustrate examples of anelectronic device including a display portion 7000 with a curvedsurface. The display surface of the display portion 7000 is bent, andimages can be displayed on the bent display surface. The display portion7000 may be flexible.

The display portion 7000 can be formed using the display device, theinput/output device, or the like of one embodiment of the presentinvention. One embodiment of the present invention makes it possible toprovide a highly reliable electronic device having a curved displayportion.

FIG. 32A illustrates an example of a mobile phone. A mobile phone 7100includes a housing 7101, the display portion 7000, operation buttons7103, an external connection port 7104, a speaker 7105, a microphone7106, and the like.

The mobile phone 7100 illustrated in FIG. 32A includes a touch sensor inthe display portion 7000. Moreover, operations such as making a call andinputting a letter can be performed by touch on the display portion 7000with a finger, a stylus, or the like.

With the operation buttons 7103, power ON or OFF can be switched. Inaddition, types of images displayed on the display portion 7000 can beswitched; for example, switching from a mail creation screen to a mainmenu screen can be performed.

FIG. 32B illustrates an example of a television set. In a television set7200, the display portion 7000 is incorporated into a housing 7201.Here, the housing 7201 is supported by a stand 7203.

The television set 7200 illustrated in FIG. 32B can be operated with anoperation switch of the housing 7201 or a separate remote controller7211. The display portion 7000 may include a touch sensor. The displayportion 7000 can be operated by touching the display portion with afinger or the like. The remote controller 7211 may be provided with adisplay portion for displaying data output from the remote controller7211. With operation keys or a touch panel of the remote controller7211, channels and volume can be controlled and images displayed on thedisplay portion 7000 can be controlled.

The television set 7200 is provided with a receiver, a modem, and thelike. A general television broadcast can be received with the receiver.When the television set is connected to a communication network with orwithout wires via the modem, one-way (from a transmitter to a receiver)or two-way (between a transmitter and a receiver or between receivers)data communication can be performed.

FIGS. 32C1, 32C2, 32D, and 32E illustrate examples of a portableinformation terminal Each of the portable information terminals includesa housing 7301 and the display portion 7000. Each of the portableinformation terminals may also include an operation button, an externalconnection port, a speaker, a microphone, an antenna, a battery, or thelike. The display portion 7000 is provided with a touch sensor. Anoperation of the portable information terminal can be performed bytouching the display portion 7000 with a finger, a stylus, or the like.

FIG. 32C1 is a perspective view of a portable information terminal 7300.FIG. 32C2 is a top view of the portable information terminal 7300. FIG.32D is a perspective view of a portable information terminal 7310. FIG.32E is a perspective view of a portable information terminal 7320.

Each of the portable information terminals illustrated in thisembodiment functions as, for example, one or more of a telephone set, anotebook, and an information browsing system. Specifically, the portableinformation terminals each can be used as a smartphone. Each of theportable information terminals illustrated in this embodiment is capableof executing a variety of applications such as mobile phone calls,e-mailing, reading and editing texts, music reproduction, Internetcommunication, and a computer game, for example.

The portable information terminals 7300, 7310, and 7320 can displaycharacters and image information on its plurality of surfaces. Forexample, as illustrated in FIGS. 32C1 and 32D, three operation buttons7302 can be displayed on one surface, and information 7303 indicated bya rectangle can be displayed on another surface. FIGS. 32C1 and 32C2illustrate an example in which information is displayed at the top ofthe portable information terminal. FIG. 32D illustrates an example inwhich information is displayed on the side of the portable informationterminal. Information may be displayed on three or more surfaces of theportable information terminal FIG. 32E illustrates an example whereinformation 7304, information 7305, and information 7306 are displayedon different surfaces.

Examples of the information include notification from a socialnetworking service (SNS), display indicating reception of an e-mail oran incoming call, the title of an e-mail or the like, the sender of ane-mail or the like, the date, the time, remaining battery, and thereception strength of an antenna. Alternatively, the operation button,an icon, or the like may be displayed instead of the information.

For example, a user of the portable information terminal 7300 can seethe display (here, the information 7303) on the portable informationterminal 7300 put in a breast pocket of his/her clothes.

Specifically, a caller's phone number, name, or the like of an incomingcall is displayed in a position that can be seen from above the portableinformation terminal 7300. Thus, the user can see the display withouttaking out the portable information terminal 7300 from the pocket anddecide whether to answer the call.

FIGS. 32F to 32H each illustrate an example of a lighting device havinga curved light-emitting portion.

The light-emitting portion included in each of the lighting devicesillustrated in FIGS. 32F to 32H can be manufactured using the displaydevice, an input/output device, or the like of one embodiment of thepresent invention. According to one embodiment of the present invention,a highly reliable lighting device having a curved light-emitting portioncan be provided.

A lighting device 7400 illustrated in FIG. 32F includes a light-emittingportion 7402 with a wave-shaped light-emitting surface and thus is agood-design lighting device.

A light-emitting portion 7412 included in the lighting device 7410illustrated in FIG. 32G has two convex-curved light-emitting portionssymmetrically placed. Thus, all directions can be illuminated with thelighting device 7410 as a center.

A lighting device 7420 illustrated in FIG. 32H includes a concave-curvedlight-emitting portion 7422. This is suitable for illuminating aspecific range because light emitted from the concave-curvedlight-emitting portion 7422 is collected to the front of the lightingdevice 7420. In addition, with this structure, a shadow is less likelyto be produced.

The light-emitting portion included in each of the lighting devices7400, 7410 and 7420 may be flexible. The light-emitting portion may befixed on a plastic member, a movable frame, or the like so that alight-emitting surface of the light-emitting portion can be bent freelydepending on the intended use.

The lighting devices 7400, 7410, and 7420 each include a stage 7401provided with an operation switch 7403 and the light-emitting portionsupported by the stage 7401.

Note that although the lighting device in which the light-emittingportion is supported by the stage is described as an example here, ahousing provided with a light-emitting portion can be fixed on a ceilingor suspended from a ceiling. Since the light-emitting surface can becurved, the light-emitting surface is curved to have a concave shape,whereby a particular region can be brightly illuminated, or thelight-emitting surface is curved to have a convex shape, whereby a wholeroom can be brightly illuminated.

FIGS. 33A1, 33A2, 33B, 33C, 33D, 33E, 33F, 33G, 33H, and 331 eachillustrate an example of a portable information terminal including adisplay portion 7001 having flexibility.

The display portion 7001 is manufactured using the display device, theinput/output device, or the like of one embodiment of the presentinvention. For example, a display device, or an input/output device thatcan be bent with a radius of curvature of greater than or equal to 0.01mm and less than or equal to 150 mm can be used. The display portion7001 may include a touch sensor so that the portable informationterminal can be operated by touching the display portion 7001 with afinger or the like. One embodiment of the present invention makes itpossible to provide a highly reliable electronic device including adisplay portion having flexibility.

FIGS. 33A1 and 33A2 are a perspective view and a side view illustratingan example of the portable information terminal, respectively. Aportable information terminal 7500 includes a housing 7501, the displayportion 7001, a display portion tab 7502, operation buttons 7503, or thelike.

The portable information terminal 7500 includes a rolled flexibledisplay portion 7001 in the housing 7501.

The portable information terminal 7500 can receive a video signal with acontrol portion incorporated therein and can display the received videoon the display portion 7001. The portable information terminal 7500incorporates a battery. A terminal portion for connecting a connectormay be included in the housing 7501 so that a video signal or power canbe directly supplied from the outside with a wiring.

By pressing the operation buttons 7503, power ON/OFF, switching ofdisplayed videos, and the like can be performed. Although FIGS. 33A1,33A2, and 33B illustrate an example where the operation buttons 7503 arepositioned on a side surface of the portable information terminal 7500,one embodiment of the present invention is not limited thereto. Theoperation buttons 7503 may be placed on a display surface (a frontsurface) or a rear surface of the portable information terminal 7500.

FIG. 33B illustrates the portable information terminal 7500 in a statewhere the display portion 7001 is pulled out with the display portiontab 7502. Videos can be displayed on the display portion 7001 in thisstate. In addition, the portable information terminal 7500 may performdifferent displays in the state where part of the display portion 7001is rolled as shown in FIG. 33A1 and in the state where the displayportion 7001 is pulled out with the display portion tab 7502 as shown inFIG. 33B. For example, in the state shown in FIG. 33A1, the rolledportion of the display portion 7001 is put in a non-display state, whichresults in a reduction in power consumption of the portable informationterminal 7500.

A reinforcement frame may be provided for a side portion of the displayportion 7001 so that the display portion 7001 has a flat display surfacewhen pulled out.

Note that in addition to this structure, a speaker may be provided forthe housing so that sound is output with the use of an audio signalreceived together with a video signal.

FIGS. 33C to 33E illustrate an example of a foldable portableinformation terminal FIG. 33C illustrates a portable informationterminal 7600 that is opened. FIG. 33D illustrates the portableinformation terminal 7600 that is being opened or being folded. FIG. 33Eillustrates the portable information terminal 7600 that is folded. Theportable information terminal 7600 is highly portable when folded, andis highly browsable when opened because of a seamless large displayarea.

A display portion 7001 is supported by three housings 7601 joinedtogether by hinges 7602. By folding the portable information terminal7600 at a connection portion between two housings 7601 with the hinges7602, the portable information terminal 7600 can be reversibly changedin shape from an opened state to a folded state.

FIGS. 33F and 33G illustrate an example of a foldable portableinformation terminal FIG. 33F illustrates a portable informationterminal 7650 that is folded so that the display portion 7001 is on theinside. FIG. 33G illustrates the portable information terminal 7650 thatis folded so that the display portion 7001 is on the outside. Theportable information terminal 7650 includes the display portion 7001 anda non-display portion 7651. When the portable information terminal 7650is not used, the portable information terminal 7650 is folded so thatthe display portion 7001 is on the inside, whereby the display portion7001 can be prevented from being contaminated or damaged.

FIG. 33H illustrates an example of a flexible portable informationterminal. A portable information terminal 7700 includes a housing 7701and the display portion 7001. The portable information terminal 7700 mayinclude buttons 7703 a and 7703 b which serve as input means, speakers7704 a and 7704 b which serve as sound output means, an externalconnection port 7705, a microphone 7706, or the like. A flexible battery7709 can be included in the portable information terminal 7700. Thebattery 7709 may be arranged to overlap with the display portion 7001,for example.

The housing 7701, the display portion 7001, the battery 7709 areflexible. Thus, it is easy to curve the portable information terminal7700 into a desired shape or to twist the portable information terminal7700. For example, the portable information terminal 7700 can be curvedso that the display portion 7001 is on the inside or on the outside. Theportable information terminal 7700 can be used in a rolled state. Sincethe housing 7701 and the display portion 7001 can be transformed freelyin this manner, the portable information terminal 7700 is less likely tobe broken even when the portable information terminal 7700 falls down orexternal stress is applied to the portable information terminal 7700.

The portable information terminal 7700 can be used conveniently invarious situations because the portable information terminal 7700 islightweight. For example, the portable information terminal 7700 can beused in the state where the upper portion of the housing 7701 issuspended by a clip or the like, or in the state where the housing 7701is fixed to a wall by magnets or the like.

FIG. 33I illustrates an example of a wrist-watch-type portableinformation terminal. The portable information terminal 7800 includes aband 7801, the display portion 7001, an input-output terminal 7802,operation buttons 7803, and the like. The band 7801 has a function of ahousing. A flexible battery 7805 can be included in the portableinformation terminal 7800. The battery 7805 may overlap with the displayportion 7001 and the band 7801, for example.

The band 7801, the display portion 7001, and the battery 7805 haveflexibility. Thus, the portable information terminal 7800 can be easilycurved to have a desired shape.

With the operation buttons 7803, a variety of functions such as timesetting, ON/OFF of the power, ON/OFF of wireless communication, settingand cancellation of silent mode, and setting and cancellation of powersaving mode can be performed. For example, the functions of theoperation buttons 7803 can be set freely by the operating systemincorporated in the portable information terminal 7800.

By touching an icon 7804 displayed on the display portion 7001 with afinger or the like, application can be started.

The portable information terminal 7800 can employ near fieldcommunication conformable to a communication standard. In that case, forexample, mutual communication between the portable information terminaland a headset capable of wireless communication can be performed, andthus hands-free calling is possible.

The portable information terminal 7800 may include the input-outputterminal 7802. In the case where the input-output terminal 7802 isincluded in the portable information terminal 7800, data can be directlytransmitted to and received from another information terminal via aconnector. Charging through the input-output terminal 7802 is alsopossible. Note that charging of the portable information terminaldescribed as an example in this embodiment can be performed bycontactless power transmission without using the input-output terminal.

FIG. 34A is an external view of an automobile 9700. FIG. 34B illustratesa driver's seat of the automobile 9700. The automobile 9700 includes acar body 9701, wheels 9702, a dashboard 9703, lights 9704, and the like.The display device or the input/output device of one embodiment of thepresent invention can be used in a display portion or the like of theautomobile 9700. For example, the display device or the input/outputdevice of one embodiment of the present invention can be used in displayportions 9710 to 9715 illustrated in FIG. 34B.

The display portion 9710 and the display portion 9711 are displaydevices or input/output devices provided in an automobile windshield.The display device or input/output device of one embodiment of thepresent invention can be a see-through display device or input/outputdevice, through which the opposite side can be seen, by using alight-transmitting conductive material for its electrodes. Such asee-through display device or input/output device does not hinderdriver's vision during the driving of the automobile 9700. Therefore,the display device or input/output device of one embodiment of thepresent invention can be provided in the windshield of the automobile9700. Note that in the case where a transistor or the like for drivingthe display device or input/output device is provided in the displaydevice or input/output device, a transistor having light-transmittingproperties, such as an organic transistor using an organic semiconductormaterial or a transistor using an oxide semiconductor, is preferablyused.

The display portion 9712 is a display device or an input device providedon a pillar portion. For example, an image taken by an imaging unitprovided in the car body is displayed on the display portion 9712,whereby the view hindered by the pillar portion can be compensated. Thedisplay portion 9713 is a display device or an input device provided onthe dashboard. For example, an image taken by an imaging unit providedin the car body is displayed on the display portion 9713, whereby theview hindered by the dashboard can be compensated. That is, bydisplaying an image taken by an imaging unit provided on the outside ofthe automobile, blind areas can be eliminated and safety can beincreased. Displaying an image to compensate for the area which a drivercannot see makes it possible for the driver to confirm safety easily andcomfortably.

FIG. 34C illustrates the inside of a car in which a bench seat is usedas a driver seat and a front passenger seat. A display portion 9721 is adisplay device or input/output device provided in a door portion. Forexample, the display portion 9721 can compensate for the view hinderedby the door portion by showing an image taken by an imaging unitprovided on the car body. A display portion 9722 is a display device orinput/output device provided in a steering wheel. A display portion 9723is a display device or input/output device provided in the middle of aseating face of the bench seat. Note that the display device orinput/output device can be used as a seat heater by providing thedisplay device or input/output device on the seating face or backrestand by using heat generated by the display device or input/output deviceas a heat source.

The display portion 9714, the display portion 9715, and the displayportion 9722 can provide a variety of kinds of information such asnavigation data, a speedometer, a tachometer, a mileage, a fuel meter, agearshift indicator, and air-condition setting. The content, layout, orthe like of the display on the display portions can be changed freely bya user as appropriate. The information listed above can also bedisplayed on the display portions 9710 to 9713, 9721, and 9723. Thedisplay portions 9710 to 9715 and 9721 to 9723 can also be used aslighting devices. The display portions 9710 to 9715 and 9721 to 9723 canalso be used as heating devices.

The display portions each including the display device or input/outputdevice of one embodiment of the present invention can be flat, in whichcase the display device or input/output device of one embodiment of thepresent invention does not necessarily have a curved surface orflexibility.

FIG. 34D illustrates a portable game machine including a housing 901, ahousing 902, a display portion 903, a display portion 904, a microphone905, a speaker 906, an operation button 907, a stylus 908, and the like.

The portable game machine illustrated in FIG. 34D includes two displayportions 903 and 904. Note that the number of display portions of anelectronic device of one embodiment of the present invention is notlimited to two and can be one or three or more as long as at least onedisplay portion includes the display device or input/output device ofone embodiment of the present invention.

FIG. 34E illustrates a laptop personal computer, which includes ahousing 921, a display portion 922, a keyboard 923, a pointing device924, and the like.

The display device or input/output device of one embodiment of thepresent invention can be used in the display portion 922.

FIG. 35A is an external view of a camera 8000. The camera 8000 includesa housing 8001, a display portion 8002, an operation button 8003, ashutter button 8004, and a connection portion 8005. A lens 8006 can beput on the camera 8000.

The connection portion 8005 includes an electrode to connect with afinder 8100, which is described below, a stroboscope, or the like.

Although the lens 8006 of the camera 8000 here is detachable from thehousing 8001 for replacement, the lens 8006 may be included in ahousing.

Images can be taken at a touch of the shutter button 8004. In addition,images can be taken at a touch of the display portion 8002 which servesas a touch panel.

The display device or input/output device of one embodiment of thepresent invention can be used in the display portion 8002.

FIG. 35B shows the camera 8000 with the finder 8100 connected.

The finder 8100 includes a housing 8101, a display portion 8102, and abutton 8103.

The housing 8101 includes a connection portion for the connectionportion 8005 of the camera 8000, and the finder 8100 can be connected tothe camera 8000. The connection portion includes an electrode, and animage or the like received from the camera 8000 through the electrodecan be displayed on the display portion 8102.

The button 8103 has a function of a power button, and the displayportion 8102 can be turned on and off with the button 8103.

The display device or input/output device of one embodiment of thepresent invention can be used in the display portion 8102.

Although the camera 8000 and the finder 8100 are separate and detachableelectronic devices in FIGS. 35A and 35B, the housing 8001 of the camera8000 may include a finder having the display device or input/outputdevice of one embodiment of the present invention.

FIG. 35C illustrates an external view of a head-mounted display 8200.

The head-mounted display 8200 includes a mounting portion 8201, a lens8202, a main body 8203, a display portion 8204, a cable 8205, and thelike. The mounting portion 8201 includes a battery 8206.

Power is supplied from the battery 8206 to the main body 8203 throughthe cable 8205. The main body 8203 includes a wireless receiver or thelike to receive video data, such as image data, and display it on thedisplay portion 8204. In addition, the movement of the eyeball and theeyelid of a user can be captured by a camera in the main body 8203 andthen coordinates of the points the user looks at can be calculated basedon the captured data to utilize the eye point of the user as an inputmeans.

The mounting portion 8201 may include a plurality of electrodes that areto be in contact with the user. The main body 8203 may be configured tosense current flowing through the electrodes with the movement of theuser's eyeball to recognize the location of his/her eye. The main body8203 may be configured to sense current flowing through the electrodesto monitor the user's pulse. The mounting portion 8201 may includesensors, such as a temperature sensor, a pressure sensor, or anacceleration sensor and display the user's biological information on thedisplay portion 8204. The main body 8203 may be configured to sense themovement of the user's head to move an image displayed on the displayportion 8204 in synchronization with the movement of the user's head.

The display device or input/output device of one embodiment of thepresent invention can be used in the display portion 8204.

At least part of this embodiment can be implemented in combination withany of the embodiments described in this specification as appropriate.

This application is based on Japanese Patent Application serial no.2014-212646 filed with Japan Patent Office on Oct. 17, 2014, the entirecontents of which are hereby incorporated by reference.

What is claimed is:
 1. A touch panel comprising: a first conductivelayer; a second conductive layer; a plurality of display elements; and ascan line, wherein the first conductive layer has an outline including afirst portion that is linear and parallel to a first direction in a planview, wherein the second conductive layer has an outline including asecond portion that is linear and parallel to the first direction in theplan view, wherein the first portion and the second portion face eachother, wherein the display element is in a position not overlapping withthe first conductive layer nor the second conductive layer, wherein thescan line has a portion extending in a second direction, and wherein anangle between the first direction and the second direction is greaterthan or equal to 30° and less than or equal to 60°.
 2. The touch panelaccording to claim 1, wherein the first conductive layer and the secondconductive layer each have a lattice shape where strips parallel to thefirst direction and strips parallel to a direction perpendicular to thefirst direction intersect with each other with openings between them,and wherein one of the openings overlaps with at least one of theplurality of the display elements.
 3. The touch panel according to claim1, wherein the display element has a polygonal shape whose two sides areparallel to the first direction in the plan view.
 4. The touch panelaccording to claim 1, further comprising: a first substrate; and asecond substrate, wherein the first conductive layer, the secondconductive layer, the display element, and the scan line are between thefirst substrate and the second substrate.
 5. The touch panel accordingto claim 4, further comprising a light-blocking layer configured toblock visible light, wherein the first substrate is provided with thedisplay element and the scan line, wherein the second substrate isprovided with the first conductive layer, the second conductive layer,and the light-blocking layer, and wherein the light-blocking layer isbetween the first conductive layer and the second substrate, and betweenthe second conductive layer and the second substrate.
 6. The touch panelaccording to claim 4, wherein the first conductive layer and the secondconductive layer are in the same plane.
 7. The touch panel according toclaim 1, wherein a distance between the first portion and the secondportion is greater than or equal to 1 μm and less than or equal to 10mm.
 8. A touch panel module comprising: the touch panel according toclaim 1, and an FPC.
 9. An electronic device comprising: the touch panelaccording to claim 1, and at least one of an antenna, a button, abattery, a speaker, a microphone, and a lens.